Your authen_LTI.conf file does have problems. You do not have "include('conf/authen_LTI_1_3.conf');" anywhere. If you are trying to use LTI 1.3, then you need that. In fact if you have the "{ '*' => 'WeBWorK::Authen::LTIAdvantage' }" line uncommented, then you you should have that inclusion in the file even if you are not using LTI 1.3.
Make sure that you don't remove the line that says "include('conf/authen_LTI_1_1.conf');". Both inclusions should be in the file with what you have in the "$authen{user_module}".
If you are trying to use LTI 1.3, then you also need $LTIVersion set to be 'v1p3'.
Once you get debugging working, then you can inspect the LTI parameters that are sent, and choose the one that you want to use for the preferred source of username. For now, set that to 'email' in authen_LTI_1_3.conf.
Note that we have office hours every Monday from 4 to 6 pm EST. Alex, Danny, and I will be there to help. The link for the Zoom meeting is https://us02web.zoom.us/j/7863786631?pwd=RXhRcGxDMmZJRDcvN1lUQStkbEJjZz09. Perhaps you could join that meeting next Monday, and we can talk about this?