Done! In your client settings you should have a NIP-05 field, just enter stu@ok0.org in there.

What this does is similar to Twitter's blue checkmark, it's a lot easier for people to remember that your account is verified as stu@ok0.org than it is for them to remember your random character NPUB. If someone tries to impersonate you, they won't have that verification so people will be able to tell it's not actually you.