go to the website (in this case, community.intersystems.com) in your default browser, go to options -> Add to your Home Screen.

Based on your default launcher, you can get to add it in app drawer as well (maybe....)

This will become a progressive web app, which creates shortcut in your home screen (and maybe app drawer), and the session will be active till you reset your browser cookies.
     

Enjoy....... Hope this helps 😄😄😄