I’ve recently recorded several audio cassettes using Audacity. Really nice to work with!
I’ve unfortunately chosen to record each tape in its own project, assuming it’d be trivial to combine them later to a single project.
However, I fail to be able to get the recordings (stored in .aup3) files from one project as additional tracks into another project.
I’ve web-searched a bit, but found contradicting things, and maybe it works on a different OS?
I’m using Xubuntu Focal 21.04.3 (64bit) and Audacity AppImage v3.1.2
Is there a reason why you need to combine them into one project? Working with very large projects is much more demanding on the computer, so it is often better to split large tasks into multiple smaller projects.