How to configure Get ID Token (Firebase auth) function for listing the record and updating single field

Hello,

I am creating Mobile APP just to list the records from Firebase real time database and update(Patch) the single field. I have not configured Sign in method. It works fine when i allow all read and write for anyone in firebase security rules.

How can I configure Secure connection for this to list the record and update the field with access token. I searched and found Get ID Token (Firebase auth) function can be used.

I appreciate any help or reference to detailed written information on this

Thanks

Add on to above my requirement is [authentication with firebase Realtime Database without user