How to manage even unregistered clients, even if the client doesn't have an email?
Go to the Clients tab > Add a new client.
Fill in the name and confirm that the client agrees to the processing of personal data.
You can then manage the client completely without restrictions from the administration, including adding memberships, registering, and deregistering.
For memberships, you’ll need to unlock the client and check the box "I know what I’m doing," because your client will never be able to make reservations on their own this way. It will always go through you (unless they take over the account later).
How can a client "take over" their account?
Enter the email address the client used to create their Zenam account, and the accounts will be linked.