I'd like to join an org, so I clicked on the "request to join" button from the login page.

If you know the slug/name of the org, please visit the link to join the org:
​<org-slug-name>.sentry.io/

This will bring you to the login page.

Next, click on "Request to Join"

This will bring you to a page to enter your email address and then submit your request.

The owner will then see this request from the Members page for them to approve or deny.

Please note:
An email will be sent to the owner/managers of the org to review the request.