Hello. Unfortunately, no. There are 3 ways:

1. The easiest way is to use Commissions feature in Payments app. In this case the app summarizes all monthly sales for each seller and generate an invoice. You (as site owner) may configure the percentage and so on. The invoice can be paid using the same Payments app.
2. Use 'Single Seller' mode. In this case you'll get all seles on your account, take your commissions and then send the rest to sellers.
3. Use Stripe Connect, but in this case all sellers should have Stripe accounts which should be connected to your main account. It requires a lot of organizational works.

For now UNA doesn't have any integrations with IUGU.