For the moment, Acast self serve is invitation only. This means the only way to get access is to get someone at Acast to invite you.
If you've received an invitation email, the rest is easy. Just hit "redeem invite".
Next, you need to create an Acast account. The username is already set (it should be the email address your invite was sent to). For safety reasons, you'll need to log in directly after sign-up, so make a note of your password.
Once you log in, you should see this:
❌ If things go wrong
If you get an error clicking the "redeem invite" button, this probably means:
The invite expired. Invites are valid for two weeks. After this you'll need to get a new one.
You already redeemed this invite. Invites can only be used once.