$fsleyes --version
fsleyes/FSLeyes version 1.3.3

$ fsleyes
   ERROR              main.py  590: initialise      - Unable to initialise OpenGL!
NotImplementedError
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/dist-packages/fsleyes/main.py", line 587, in initialise
    fslgl.getGLContext(ready=realCallback)
  File "/usr/local/lib/python3.9/dist-packages/fsleyes/gl/__init__.py", line 490, in getGLContext
    thismod._glContext = GLContext(**kwargs)
  File "/usr/local/lib/python3.9/dist-packages/fsleyes/gl/__init__.py", line 658, in __init__
    self.__createWXGLCanvas()
  File "/usr/local/lib/python3.9/dist-packages/fsleyes/gl/__init__.py", line 804, in __createWXGLCanvas
    attrs = WXGLCanvasTarget.displayAttributes()
  File "/usr/local/lib/python3.9/dist-packages/fsleyes/gl/__init__.py", line 1097, in displayAttributes
    attrs = wxgl.GLAttributes()
SystemError: <class 'wx._glcanvas.GLAttributes'> returned a result with an error set

$ glxinfo
name of display: :1
display: :1  screen: 0
direct rendering: Yes
server glx vendor string: NVIDIA Corporation
server glx version string: 1.4
server glx extensions: