For a small scale, one relatively secure, but somewhat inflexible, approach is to generate a large batch (say 1 million) public keys (use a deterministic wallet like Electrum uses so they're all governed by one secret key) and just store them on the payment platform site, issuing one per order. You have a distinct address and no private keys have to be online.

If you want the whole deal of getting USD or similar in your bank automatically, I would suggest investigating payment processor services that wrap all of that for you.

For getting USD, I'm a Salvadoran citizen where BTC is legal tender so I think I can exchange all coins for BTC and exchange for USD at the bank

But I would want a long term solution that I don't need to maintain

Honest question: Why not use a regular payment processor instead? E.g. Klarna (HQ in Sweden) or SecurionPay (HQ in Switzerland). (There are several other alternatives, those are just two examples.)

Addendum: Another alternative that might be interesting: https://www.skrill.com/en/business/

This isn't just about avoiding US jurisdiction but also let users pay and receive payment with ideally the alt coin of their choice (or one of a few choices). In LATAM conventional banking adoption is low, it's unlikely many people would have a credit/debit card, and the exchange rate and associated fees are very unfavorable

The problem with US payment processors is you're subject to US laws and penalties, but for the most part my customers won't be in the US and I'd prefer to avoid the jurisdiction

So what jurisdiction do you prefer then?

Target market is LATAM, maybe outside of five eyes is enough?

Wow I will try