I want to create a website when users on singing up will get a unique address and after getting my websites service,they can withdrawal the money also automatically. Is that bitcoin integration free ? Plz help i am noobie to this.
Sounds that right way for you would be to run Bitcoin Core (full node) and develop your own deposit / withdrawal system from scratch. Relying on third party APIs has potential problems with reliablity, security and user's privacy.
- If you plan that single user can deposit BTC multiple times, best practice is to change deposit address with each new deposit for the user. Address generation is free. This helps both user's and overall Bitcoin privacy, without downsides from your side (apart from some little more effort in coding solution).
- When user withdraw their BTC, it is best practice to batch their transactions together, it will take less space in blockchain and you will save on transaction fees. Basically, there is no point in sending out another transaction, before previous one is confirmed, in that time you should just add withdrawals into queue and then combine them together in a single withdrawal transaction. Final transaction confirmation time 99% cases will be the same, but it will be cheaper.
This is a good book if you want to understand how Bitcoin works from technical side - https://github.com/bitcoinbook/bitcoinbook.