I had a similar challenge.

The self custody wallets I use regularly are not easily used with damus since Lightening primarily works with open invoices. There were workarounds that set up a permanent lightening address but then you either needed to set that up through a centralized account or a fairly complicated work around.

I ended up just moving a small amount into a Damus compatible centralized wallet exclusively for sending zaps. But that’s not a great solution, since it’s kind of against the point of a decentralized social protocol working with decentralized money & payments 🤷🏽‍♂️. So if you find a good solution would love hear it.