@leocg I tried it, but it wasn't working for me. Someone else replied with an add-on for Opera that I'm going to test run, though!

I downloaded Grammarly a while ago, but noticed that it is not possible to add the app's extension to your Opera browser. Is there any way that the Opera team could figure out a way to allow that? I use Grammarly to double-check things I missed in emails and fanfiction, and don't particularly like having to copy and paste all of my writing into the Grammarly tab.