https://github.com/btcpayserver/node-btcpayBTCpay has a node.js client, pretty easy to implement, completely open source and has LN support.
DO NOT confuse this with Bitpay, the AML/KYC clusterfuck known for their partnership with Bitmain, which many do, and that's how you end up being put on "a list".
I think that kyc is no problem for a merchant in a legit website. Is this the main problem with bitpay? I saw many people recommending bitpay already.
I know btcpay is very good, but I think bitpay is even older.