Sharing/export students' apps for evaluation purposes


I am teacher and this academic year I would like to give a class on building apps with low-code tools. I am evaluating AppGyver as a possibile candidate.
However, I give students a final mark based on a project assignment. So I am wondering how they can share their apps with me in such a way I can see their work and evaluate them.

As far I have understood they cannot share their apps with me, unless I have a BTP account. Is it enough just to have the free tier account to accomplish that?
Are there any other options? Is it possible to export from one account and re-import in another account?

thank you