Can you share the message it replies with? The tutorial shouldn’t require a specific trust level. You can reply to Discobot even before you are allowed to create personal messages, and you usually receive a message right after sign up.
If you didn’t receive one, usually, a message that tells them to start the tutorial is enough. Something like this: click for message draft (it can be different depending on your language preference). Then you do what it tells you and bookmark the post.