If you're transferring your Mastodon account to another server, be careful not to press the "Archive Request" button.
This button is not used in the transfer process, it's only there for you to download a copy of your data for personal use. The archive produced by this button cannot be uploaded anywhere.
There's a step-by-step guide to the full transfer process (including transferring followers, follows, mutes, blocks and bookmarks) at https://fedi.tips/transferring-your-mastodon-account-to-another-server.