can the invoices be automated ? At this point i do it manually either name@wallet.com and the amt, or a wallet invoice - and while nobody has paid me in sats lol, it triggers conversations. But for higher volume of sales or commerce sales that ties to POS system like Square, Xero, Shopify - would be kinda nice if there is an API or an automated invoice generation i guess?
Discussion
An xpub is all that is needed for payments on the chain. You can export hundreds of address upfront, and so you have your basic raw API at hand in a text file.
The problem is integrating it smoothly with the user billing system. Perhaps you can use something like https://books.libreoffice.org/en/WG71/WG7114-MailMerge.html for a basic automation (but you miss the qrcode goodie).
For LN you can use some service like LNbits, I suppose there are several that expose an API, along with a GUI for the invoicing system.