@Zhanat
In the first SSID where you have WPA2/3 enabled, then the data between the AP and the devices on that specific SSID are encrypted using WPA2/3 algorithms. This will be secured via the passkey
The Portal however, it wil be open security as its free for anyone to connect. You are not encrypting / protecting the wifi to allow anyone to connect, you are only allowing them internet access once they have gone via the portal. However its not encrypted, no.. to encrypt you would need to enable WPA2 or WPA3 alongside, however then its a public password for all to use so really it makes the encryption redundant (as everyone knows the passcode)