As per your requirement, you can do this by installing your own BITCOIN core. you can Interact with nodes by PHP for Creating wallets, Address, Balance, Transaction.
There wont be no fees for internal transaction. No API Limits (Since it runs on your own server)
Here is the easy video instruction that might be usefull..
www.shorturl.at/bfwGLAnother popular method would be bitcore-lib.
https://github.com/bitpay/bitcore#bitcoreHope this helps!!

Hello,
Without working with a third tier service that could take fees or limit my account, I would like to create wallets, check transactions and send btc with PHP.
Each user would have a unique public key to make donations. All I want is to be able to generate a unique one for each user, and to check for transactions regularly, in order to transfer its balance to a main wallet.
So what I need is:
- Create wallets (Public & Private key)
- Create transactions
- Check for transactions and balances
I want to be as dependent as possible, so without API keys or something like this.
How can I perform this?
Thank you by advance