Get Avast Passwords working with Firefox Message

I tried avast passwords and do not like it, so I uninstalled it. But I continue to get this message every time I open firefox and a similar window comes up when I launch chrome:

Get Avast Passwords working with Firefox

Ho can I disable these windows when I launch a new browser session?

Please make sure that the Passwords extensions have been removed:

Mozilla Firefox:
Please click the ‘Open menu’ menu button in the top right corner (three horizontal lines) > click “Add-ons” > click the “Remove” button to the right of Avast Passwords

Google Chrome:
Click the menu/more icon in the top right corner (three circles in a vertical line) > click “More tools” > click “Extensions” on the expanded menu > click “Remove” on the Avast Passwords tile > click “Remove” on the pop-up that opens