GPS Send Invitation and Custom Waiting Room

Hello, I am developing a realtime card game by using GPS. I completed the game and publish on PlayStore with critical problems caused by Google Play Services. One of these problems is inviting players.
At first and currently, I use the method “CreateWithInvitationScreen” which is presented by Google.
It’s functionality is good but not enough. I need more specific Invitation room.
So, I got the players google ID and saved them to SQL by using UnityWebRequest. Now I have a list of players who download my game with their GoogleIDs. Then, I prepared a custom Invitation room and get player id’s from SQL. It works perfectly but the problem is, Invitation method of GPS. I couldnt find a command that will send Invitation to the other selected players. So please advice me a way to solve this problem. Thanks

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