Just to save others from wasting their time (and free trial): The Copilot extension in full Visual Studio (i.e. NOT VS Code) is super terrible, broken, and buggy. It is so bad it is worse than nothing (literally, it can make Visual Studio lag out). But don't take my word for it, read the reviews:

https://marketplace.visualstudio.com/items?itemName=GitHub.c...

This is the polar opposite of VS Code where it works super well and reviews great accordingly. In my opinion if you're a Visual Studio developer who wants AI assist, you'll need to figure out how to open your solution in VS Code instead to use Copilot or just pay the $20/month for ChatGPT Plus then copy/paste.

PS - This isn't a version specific thing, it has been broken since launch. They've been replying to reviews with "Try Copilot version [vNext] with Visual Studio [latest]" since last December to last week, yet the one-star reviews keep coming in unabated. Funny enough they recently replied to a complaint with "The VS Code version does this!"