How to click on this webpage button with AppleScript - safari

Question

I am having trouble clicking on the "search" button on a particular website. The website is a subscription service, so I am attaching a picture of the page pulled up in "inspect" mode as well as my code.
My code:
set myURL to "https://www.uptodate.com/contents/search"
tell application "Safari"
activate
make new document with properties {URL:myURL}
end tell
tell application "System Events"
repeat until exists (UI elements of groups of toolbar 1 of window 1 of application process "Safari" whose name = "Reload this page")
delay 0.3
end repeat
end tell
inputByID("tbSearch", "myVar")
clickClassName("newsearch-submit", 0)
###InputByID###
to inputByID(theId, theValue)
tell application "Safari"
do JavaScript "document.getElementById('" & theId & "').value ='" & theValue & "';" in document 1
end tell
end inputByID
###ClickByClass###
to clickClassName(theClassName, elementnum)
tell application "Safari"
do JavaScript "document.getElementsByClassName('" & theClassName & "')[" & elementnum & "].click();" in document 1
end tell
end clickClassName

Answer 1

As an alternative, you can use UI Scripting, where System Events preforms some keystrokes.
The following example AppleScript code works for me in macOS High Sierra1:
set myURL to "https://www.uptodate.com/contents/search"
tell application "Safari"
activate
make new document with properties {URL:myURL}
end tell
tell application "System Events"
repeat until (accessibility description of ¬
button 1 of UI element 1 of every group of toolbar 1 of window 1 of ¬
process "Safari" whose name = "Reload this page") contains "Reload this page"
delay 0.5
end repeat
end tell
tell application "Safari"
do JavaScript "document.getElementById('tbSearch').value ='PPE';" in document 1
end tell
tell application "System Events"
keystroke space
key code 51 -- # Press the delete key to remove the space.
keystroke return
end tell
1 NOTE: For macOS Mojave and later, change UI element 1 to UI element 2 in the repeat loop above.
Note: The example AppleScript code is just that and does not contain any error handling as may be appropriate. The onus is upon the user to add any error handling as may be appropriate, needed or wanted. Have a look at the try statement and error statement in the AppleScript Language Guide. See also, Working with Errors. Additionally, the use of the delay command may be necessary between events where appropriate, e.g. delay 0.5, with the value of the delay set appropriately.

Answer 2

I played around with this and of course not having a subscription cannot truly test it but perhaps you can see if this works for you - it seemed to be working:
tell application "Safari"
--activate --can work with or w/o Safari in foreground
set myURL to "https://www.uptodate.com/contents/search"
make new document with properties {URL:myURL}
delay 5 -- just waits for (hopefully) the page to load
set d to do JavaScript "document.forms[0][0].value = 'joint pain'" in document 1
do JavaScript "document.forms['searchForm'].submit();" in document 1
end tell