Album Art from PC

Good Evening,

How do update tag information from my PC?

I had a bunch of albums that I couldn't get the art for online via the Tag sources. However, I found the covers and have the .jpgs on my PC.

I'm can't figure out if I can update the tag info this way with Mp3tag and didn't see any other threads about it.

TIA

Actually, there are loads of threads. e.g. this one:
Import any image in [album] folder and apply as album art for multiple albums
If you want to attach album art or covers album by album, then select the files that should get the same set of covers, open the extended tags dialogue (Alt-T) and press the NEW button on the very right.
This lets you navigate to the bitmap.
Save the changes by pressing OK to close all dialogues and you are done - for that album.