I'm getting an error when updating my username in Sentry.

If you sign up with a Sentry account with your e-mail, the option to change username does not exist.

The option to change username only exists when you create your account through other means as Sentry assigns you a random ID, which you can then change to a verified e-mail.

Steps:

To change your username, go to Settings > Account Details: https://sentry.io/settings/account/details/

The username field will only be available for certain users who did not set up their Sentry account via their e-mail. Once the username has been changed to a verified email, the field will be gone.
​Please note: You will only be able to change this to a verified email once.