Possible to remove invoice expiration and amount?

[tonydavis629]

I would like to operate my shop as a deposit address for my customers, so they purchase credits with their deposits. It seems that btcpay is designed entirely for selling goods, and so invoices are generated for each payment. Is there any way to operate without invoices, and just generate deposit addresses for my users? I have particular issues with how this works with lightning, because the generated invoice must have a certain amount, whereas I want just a deposit address for the user to decide the amount. The best solution I see is setting the invoice expiration to 99999 minutes, and setting a fixed invoice/deposit amount for my lightning users. Neither of these workarounds are great.