If you have fof/user-bio
installed, the key you are looking for is bio
😉 you should be able to grab that attribute through an API call to the users
endpoint under your respected user id or username.
For example, this is my info you can grab from the users
endpoint:
https://discuss.flarum.org/api/users/Ralkage
or
https://discuss.flarum.org/api/users/8906
will suffice.
If you're trying to add the bio field elsewhere in the Flarun frontend (let's say at the end of a Discussion with your avatar, username, and bio as they typically have on news reporting sites), it would require you to write a separate extension that checks if the extension is installed and for you to be able to place the field elsewhere in terms of the frontend.