So the button for Retrieve is not showing. Gather is showing, but I can't get the retrieve to work no matter what I do.

"No matter what I do" - Please elaborate on what you tried

ItemRetriever needs to be installed, and the backpacks.retrieve (not to be confused with backpacks.fetch) permission needs to be granted to the player.

Yes, I have ItemRetriever downloaded and I have the permission added to me. I don't see it on the backpack at all. Only thing I see is the gather option.

Can you confirm you have ItemRetriever loaded, by running "o.reload ItemRetriever". Also confirm you have the permission by running "o.grant group default backpacks.retrieve" (even if you don't intend to give the permission to the default group long term, this is just to baseline). Paste the output of those commands here.

It's loaded and the permission is running right now.
12/08 12:48:39 | ItemRetriever was compiled successfully in 1504ms