You can set up subscription check so that only members of your channel or group will be able to activate a check.
For this, create a new multi-use check, choose Edit Restrictions in the check settings, tap Join to Activate… and then tap Connect… Add @CryptoBot as an admin to your channel or group with a permission to invite users enabled.
Open the desired multi-use check and go to the Edit Restrictions.
Click to the Join to Activate.
Connect the channels or groups where you want to check subscriptions.
The connected channels or groups will appear in the list.
