Create the proof
Log in to your Mastodon instance and click on Edit profile.
Add a new item under Profile metadata with a label of your choosing — OpenPGP, Cryptography or Keyoxide could be a meaningful label. The value should be the proof.
Add the claim…
The claim looks as follows:
Make sure to replace DOMAIN and USERNAME.
…to a signature profile:
Follow the instructions provided here. The claim should look like:
…to an OpenPGP profile:
Follow the instructions provided here. The notation should look like: