Sending of login credentials in a URL is only safe if you use secure HTTP (i.e. https://...
). The documentation for Adobe Connect that you linked mentions this in a note, but many of the example that they show use plain http://...
. Very misleading.
Once you are logged in you receive a session, which you have to send in place of the credentials with future requests. The risk is lower with session IDs, but regardless, it is a good idea to also protect the session ID by sending all requests over secure HTTP.
Then you have a second problem to solve. The user credentials need to travel from the user's computer to your own server before you send them to Adobe Connect. Your server should also be on secure HTTP.
Finally, in the same way Adobe Connect "remembers" you with the session ID that you pass with all requests, you will need to have a session for each of your users so that each time they request a page you remember them and know what Adobe session to use for the requests that you need to send.
For your own session IDs you can just reuse the Adobe Connection session ID, you just send it to your user in a cookie and then you'll get it back each time they request a page. A more robust solution requires you to generate your own session IDs that are different from Adobe's and associate your sessions with Adobe sessions in your user database table.
There is an extremely useful extension called Flask-Login that does management of user sessions for authentication. It may save you some time if you decide to implement your own user sessions.
Good luck.