Everyone writes what he thinks. So, it is hard, to be sure of anything. I am sick and tired of that. If anyone of you know, what is truly authentic knowledge, please, be so kind and let me know.
Please, help me, how can I put on an address to pay into, on my website, that my clients could use.
They require that, and I don't know how, if an address is a one-time thing.
If I am not wrong then you are asking about how to accept bitcoin on your website for sell products. So just make it simple, if you don't have much knowledge about bitcoin Marchant then you have to use third party wallet, like coinbase, coinpayments and so on. Coinbase required KYC, so if you do not have problems with KYC then you may use it, there is no any deposit fees (no fees for receive funds) and easy integration. But I will not recommend you to use third party wallet, it's just an easy option. Third party service means you do not have control of your fund & private keys because they are custodial wallet.
I will suggest to use
BTCPay server, it's open source payment getaway and you will have control of your fund with private keys. But you should have some basic technical knowledge in order to use it. You may use your own server, or you may use third party server. Using your own server would cost you and should have full technical knowledge. Using their party servers you have to trust them although private keys with you. Here is some
third party hosting service for BTCPay, I think there is not much problem with third party hosting servers. There is also no need any documents like KYC.
Both option has given above, now you have to choose which one is best option for you.