Create the proof
Go to mov.im and log in using your XMPP credentials. Click on Configuration and append the proof to the About Me section.
Alternatively, use native XMPP clients that support editing the vCard data such as Gajim.
If you have followed these steps and the identity proof still doesn't work, it could be that your XMPP instance is running Prosody and configured to restrict vCard access. Contact your XMPP administrator to ask if this is the case and whether it could be changed.
Add the claim…
The claim looks as follows:
Make sure to replace XMPP_ID.
…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: