yes, i found about this electrum too yesterday.
i can generate a lot of addresses to give to the clients.
next step, should i link with blockchain api to read transaction history of each btc address?
or should i setup my own bitcoin server to do it?
but the syncing process will take a lot of time.
any opinion?
What exactly your business is?
Since you mention " that your clients will make monthly payment" in your business I think you are going to build a business with membership subscription? Am I right?
If your business is built on Wordpress I suggest you find "membership subscription plugin" Integrates with WooCommerce and then use BTCpayserver as a payment gateway.
All transactions will be recorded on Woocommerce so if you are going to read the transaction history all information can found on Woocommerce order page like the BTC address where they sent and how much they pay.
Btcpay has two options the self-hosted or you can use the 3rd party hosting. If you choose a self-hosted you will need to host it on your own(Don't worry they made it easy one-click deployment if you are going to host them on azure,web-deployment or Google cloud) check their documentation for more info
https://docs.btcpayserver.org/ BTCpay self-hosted requires fully sync before you can use it but if you don't want to wait you can use their mainnet demo or 3rd party hosting like btcpayjungle.com
BTCpay only requires your wallet xPUB or master public key so that all addresses generated from your customers are from your wallet(Which is fully controlled by you).