Are there any way on how to add or CRUD multiple users in firebase(authentication) without the firebase admin sdk?
I do have this add user function in my web, however after of some research and google-ing, I found at that it needs to have a firebase admin sdk. Is firebase admin sdk is really necessary for doing this functions and are there any payment/billing when using it? Thanks
Any suggestions are appreciated
It sounds like you want to create multiple users, which is considered an administrative operation. While you could do this with a client-side SDK (as shown in Firebase kicks out current user), the recommended, idiomatic approach is to use a Firebase Admin SDK for this in a trusted environment (such as your development machine, a server that you control, or Cloud Functions/Cloud Run).
There is no cost to using the Admin SDK, as otherwise that would be indicated on the Firebase pricing page.