If you’d like to use your own hotspot for free, or whitelist computers, there are 3 possibilities.
You can have master accounts (2 per location for free) in case of pay per use or voucher based locations. With these master accounts, 2 people (owners or staff) can log in to the hotspot for free. To create a master account you need to login to the control center, and click on MANAGE > Master Accounts from the list. Master accounts are valid for 6 months, a renew button will appear 1 month before expiration. You can renew the account with this button for another 6 months, counted from the date of renewal.
In some firmwares, like DD-WRT, OpenWRT, Open-Mesh you can create a secondary SSID which you can password protect, so only those can access it who knows the password.Related article: Create multiple SSIDs
In some firmwares, like OpenWRT or Mikrotik you can allow MAC addresses to use the hotspot without authentication (Local Macauth). Related article: Macauth
The advantage of the first one is that you can assign a bandwidth and traffic limits to the master accounts, just like to normal hotspot users.