Where do I find "Classic Application Support"?
Braveheart Pinephone needs that for Libertine, according to the message from the Classic Application Manager
I'm not entirely sure what exactly you (or your device) is asking for there, but graphical applications do not currently work with Libertine on Pinephone. You can only use CLI tools and apps with it currently.
@doodah Like he said, Libertine isn't fully working yet on the pinephone. You can already create a container but UI programs aren't working since xwayland isn't working yet.
Libertine containers can be created in the settings app. It's basically a proot container which is the supported way of installing stuffs via apt.