How can i link a specific app to an existing login in 1password

Hi chaosphysik​! Thanks for writing in. 

The short answer is you can't paste in an Android app link the way you might with a URL to manually link an item. However, if the app in question works with our autofill service there is another way to add it. You can try these steps:

1. Open an app that you have a login for, then tap a sign in field. 
2. Tap the "Open 1Password" prompt that appears, then unlock 1Password if requested.
3. Search for and select the corresponding login. 
4. Select "Always Allow" in the prompt.

After selecting "Always Allow" the login will now be linked to the app. 

You noted that you don't see a prompt from 1Password when trying to sign into your banking app. It's not uncommon for financial apps to block or otherwise disallow autofill which may be the case here. You can try long pressing a sign in field in the app, then select Autofill or ⋮  > Autofill if it appears in the context menu. If you'd like to share which banking app you're using, we can also take a look for any issues. 

Thanks again!