How to trigger a login on an URL?

What are you trying to achieve?

Hi community, noob question - I am trying to build an app to take an input and then login to a website for an action using the input.
I am stuck with the ‘session id’ error. Trying to use Airtop to create a session first, open the URL in there and then scrape the page to find user name and password field. does this sound like the right approach? any tips on getting past the errors is highly appreciated.

Thanks in advance!