Error I don't understand with Geoplotlib when trying to display a trajectory on a map - keyerror

Question

I'm trying to display a trajectory on a map using geoplotlib but I have the following error that I don't understand:
Traceback (most recent call last):
File "C:\Users\jlouvet\anaconda3\lib\site-packages\pandas\core\indexes\base.py", line 3361, in get_loc
return self._engine.get_loc(casted_key)
File "pandas_libs\index.pyx", line 76, in pandas._libs.index.IndexEngine.get_loc
File "pandas_libs\index.pyx", line 108, in pandas._libs.index.IndexEngine.get_loc
File "pandas_libs\hashtable_class_helper.pxi", line 5198, in pandas._libs.hashtable.PyObjectHashTable.get_item
File "pandas_libs\hashtable_class_helper.pxi", line 5206, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 'lon'
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "C:\Users\jlouvet\anaconda3\lib\site-packages\geoplotlib_init_.py", line 32, in _runapp
app.start()
File "C:\Users\jlouvet\anaconda3\lib\site-packages\geoplotlib\core.py", line 364, in start
self.proj.fit(BoundingBox.from_bboxes([l.bbox() for l in self.geoplotlib_config.layers]),
File "C:\Users\jlouvet\anaconda3\lib\site-packages\geoplotlib\core.py", line 364, in
self.proj.fit(BoundingBox.from_bboxes([l.bbox() for l in self.geoplotlib_config.layers]),
File "C:\Users\jlouvet\anaconda3\lib\site-packages\geoplotlib\layers.py", line 159, in bbox
return BoundingBox.from_points(lons=self.data['lon'], lats=self.data['lat'])
File "C:\Users\jlouvet\anaconda3\lib\site-packages\pandas\core\frame.py", line 3458, in getitem
indexer = self.columns.get_loc(key)
File "C:\Users\jlouvet\anaconda3\lib\site-packages\pandas\core\indexes\base.py", line 3363, in get_loc
raise KeyError(key) from err
KeyError: 'lon'
My code is as follows:
import os
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import geoplotlib
import pyglet
os.chdir(r'C:\Users\jlouvet\Desktop\Données_bateau\CASINO_CSV')
data = pd.read_csv("20210817.csv", sep=';')
trajectory = data[['Latitude', 'Longitude']]
geoplotlib.dot(trajectory)
geoplotlib.show()
Thank you in advance for your help.