I use Eclair on my phone which is connected to my online btcpay node. Haven't tried any other wallets because this is working like a charm.
Specify deposit amount to deposit and get invoice.
Where are you hosting btcpay? Do you have any costs to have that up?
I didn't even know you could connect eclair mobile to btcpay. Very cool.
With connect I mean open a channel with my BTCPay node, so all the payments I do go through my online node.
That's quite smart actually.