Paddle alternatives?

Hi there,

I'm currently doing research for the payment integration for my SaaS. Paddle looks like the best candidate but unfortunately, my app has the invoice feature, which Paddle doesn't allow to sell on their platform.

I used 2checkout in the past. It was okay but the integration takes a lot of time. I'm living in SouthEast Asia so Stripe and Braintree are inaccessible.

I'm looking forward to your advice!