PROJ string not recognised - gdal

Question

I've used the GDAL command window to run projinfo -s epsg:27700 -t epsg:3857 --spatial-test intersects
From the list of operations I have found the one which I want to use in my gdalwarp comand. It is as follows:
Operation No. 2:
unknown id, Inverse of British National Grid + OSGB36 to WGS 84 (6) + Popular Visualisation Pseudo-Mercator, 2 m, United Kingdom (UK) - Great Britain - England and Wales onshore, Scotland onshore and Western Isles nearshore including Sea of the Hebrides and The Minch; Isle of Man onshore.
PROJ string:
+proj=pipeline
+step +inv +proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000
+y_0=-100000 +ellps=airy
+step +proj=push +v_3
+step +proj=cart +ellps=airy
+step +proj=helmert +x=446.448 +y=-125.157 +z=542.06 +rx=0.15 +ry=0.247
+rz=0.842 +s=-20.489 +convention=position_vector
+step +inv +proj=cart +ellps=WGS84
+step +proj=pop +v_3
+step +proj=webmerc +lat_0=0 +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84
WKT2:2019 string:
CONCATENATEDOPERATION["Inverse of British National Grid + OSGB36 to WGS 84 (6) + Popular Visualisation Pseudo-Mercator",
SOURCECRS[
PROJCRS["OSGB36 / British National Grid",
BASEGEOGCRS["OSGB36",
DATUM["Ordnance Survey of Great Britain 1936",
ELLIPSOID["Airy 1830",6377563.396,299.3249646,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4277]],
CONVERSION["British National Grid",
METHOD["Transverse Mercator",
ID["EPSG",9807]],
PARAMETER["Latitude of natural origin",49,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8801]],
PARAMETER["Longitude of natural origin",-2,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8802]],
PARAMETER["Scale factor at natural origin",0.9996012717,
SCALEUNIT["unity",1],
ID["EPSG",8805]],
PARAMETER["False easting",400000,
LENGTHUNIT["metre",1],
ID["EPSG",8806]],
PARAMETER["False northing",-100000,
LENGTHUNIT["metre",1],
ID["EPSG",8807]]],
CS[Cartesian,2],
AXIS["(E)",east,
ORDER[1],
LENGTHUNIT["metre",1]],
AXIS["(N)",north,
ORDER[2],
LENGTHUNIT["metre",1]],
ID["EPSG",27700]]],
TARGETCRS[
PROJCRS["WGS 84 / Pseudo-Mercator",
BASEGEOGCRS["WGS 84",
ENSEMBLE["World Geodetic System 1984 ensemble",
MEMBER["World Geodetic System 1984 (Transit)"],
MEMBER["World Geodetic System 1984 (G730)"],
MEMBER["World Geodetic System 1984 (G873)"],
MEMBER["World Geodetic System 1984 (G1150)"],
MEMBER["World Geodetic System 1984 (G1674)"],
MEMBER["World Geodetic System 1984 (G1762)"],
MEMBER["World Geodetic System 1984 (G2139)"],
ELLIPSOID["WGS 84",6378137,298.257223563,
LENGTHUNIT["metre",1]],
ENSEMBLEACCURACY[2.0]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4326]],
CONVERSION["Popular Visualisation Pseudo-Mercator",
METHOD["Popular Visualisation Pseudo Mercator",
ID["EPSG",1024]],
PARAMETER["Latitude of natural origin",0,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8801]],
PARAMETER["Longitude of natural origin",0,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8802]],
PARAMETER["False easting",0,
LENGTHUNIT["metre",1],
ID["EPSG",8806]],
PARAMETER["False northing",0,
LENGTHUNIT["metre",1],
ID["EPSG",8807]]],
CS[Cartesian,2],
AXIS["easting (X)",east,
ORDER[1],
LENGTHUNIT["metre",1]],
AXIS["northing (Y)",north,
ORDER[2],
LENGTHUNIT["metre",1]],
ID["EPSG",3857]]],
STEP[
CONVERSION["Inverse of British National Grid",
METHOD["Inverse of Transverse Mercator",
ID["INVERSE(EPSG)",9807]],
PARAMETER["Latitude of natural origin",49,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8801]],
PARAMETER["Longitude of natural origin",-2,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8802]],
PARAMETER["Scale factor at natural origin",0.9996012717,
SCALEUNIT["unity",1],
ID["EPSG",8805]],
PARAMETER["False easting",400000,
LENGTHUNIT["metre",1],
ID["EPSG",8806]],
PARAMETER["False northing",-100000,
LENGTHUNIT["metre",1],
ID["EPSG",8807]],
ID["INVERSE(EPSG)",19916]]],
STEP[
COORDINATEOPERATION["OSGB36 to WGS 84 (6)",
VERSION["UKOOA-Pet"],
SOURCECRS[
GEOGCRS["OSGB36",
DATUM["Ordnance Survey of Great Britain 1936",
ELLIPSOID["Airy 1830",6377563.396,299.3249646,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
CS[ellipsoidal,2],
AXIS["geodetic latitude (Lat)",north,
ORDER[1],
ANGLEUNIT["degree",0.0174532925199433]],
AXIS["geodetic longitude (Lon)",east,
ORDER[2],
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4277]]],
TARGETCRS[
GEOGCRS["WGS 84",
ENSEMBLE["World Geodetic System 1984 ensemble",
MEMBER["World Geodetic System 1984 (Transit)"],
MEMBER["World Geodetic System 1984 (G730)"],
MEMBER["World Geodetic System 1984 (G873)"],
MEMBER["World Geodetic System 1984 (G1150)"],
MEMBER["World Geodetic System 1984 (G1674)"],
MEMBER["World Geodetic System 1984 (G1762)"],
MEMBER["World Geodetic System 1984 (G2139)"],
ELLIPSOID["WGS 84",6378137,298.257223563,
LENGTHUNIT["metre",1]],
ENSEMBLEACCURACY[2.0]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
CS[ellipsoidal,2],
AXIS["geodetic latitude (Lat)",north,
ORDER[1],
ANGLEUNIT["degree",0.0174532925199433]],
AXIS["geodetic longitude (Lon)",east,
ORDER[2],
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4326]]],
METHOD["Position Vector transformation (geog2D domain)",
ID["EPSG",9606]],
PARAMETER["X-axis translation",446.448,
LENGTHUNIT["metre",1],
ID["EPSG",8605]],
PARAMETER["Y-axis translation",-125.157,
LENGTHUNIT["metre",1],
ID["EPSG",8606]],
PARAMETER["Z-axis translation",542.06,
LENGTHUNIT["metre",1],
ID["EPSG",8607]],
PARAMETER["X-axis rotation",0.15,
ANGLEUNIT["arc-second",4.84813681109536E-06],
ID["EPSG",8608]],
PARAMETER["Y-axis rotation",0.247,
ANGLEUNIT["arc-second",4.84813681109536E-06],
ID["EPSG",8609]],
PARAMETER["Z-axis rotation",0.842,
ANGLEUNIT["arc-second",4.84813681109536E-06],
ID["EPSG",8610]],
PARAMETER["Scale difference",-20.489,
SCALEUNIT["parts per million",1E-06],
ID["EPSG",8611]],
OPERATIONACCURACY[2.0],
ID["EPSG",1314],
REMARK["Commonly referred to as the ""OSGB Petroleum transformation"". For a more accurate transformation see ETRS89 to OSGB36 / British National Grid (3) (code 7953)."]]],
STEP[
CONVERSION["Popular Visualisation Pseudo-Mercator",
METHOD["Popular Visualisation Pseudo Mercator",
ID["EPSG",1024]],
PARAMETER["Latitude of natural origin",0,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8801]],
PARAMETER["Longitude of natural origin",0,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8802]],
PARAMETER["False easting",0,
LENGTHUNIT["metre",1],
ID["EPSG",8806]],
PARAMETER["False northing",0,
LENGTHUNIT["metre",1],
ID["EPSG",8807]],
ID["EPSG",3856]]],
USAGE[
SCOPE["unknown"],
AREA["United Kingdom (UK) - Great Britain - England and Wales onshore, Scotland onshore and Western Isles nearshore including Sea of the Hebrides and The Minch; Isle of Man onshore."],
BBOX[49.797,-8.818,60.935,1.92]]]
However, when I copy the PROJ string as the t_srs I am getting an error PROJ: proj_create: unrecognized format / unknown name
I'm not quite sure how to pass the PROJ string in correctly as I am new to it. I know I can also pass it in as WKT but that seems like an awful lot of text to pass in.
Is there some method to refining the information and passing it in correctly?
It is specifically this transformation method I want, so I need to ensure I pass it through correctly