This week I am also working on a project to help more merchants onboard lightning network..

My approach is similar to stripe payment link, here is the whole process:

For merchants:

1. In a web page, the merchants leave their lightning network address(they can get from https://lightningaddress.com/)
2. The name / description / amount of products
3. The return and webhook url

Then the service will generate a reusable payment link

For customers:

1. Click the payment link, get product detail and invoice QR code which is a hodl invoice based on the lightning address (inspired by https://lnproxy.org/)
2. After the hodl invoice get paid, the service will route the original invoice and settle the hodl invoice, then send webhook to merchants.

This will have much better experience than stripe or open node:

No KYC / Very low Fee / No chargeback/ Even no need to sign up/ Service don't hold money.

Any merchants can sell any thing online and accept bitcoin!