Peplink Balance 20x - 2 WAN

I bought the peplink balance 20x, because I have 2 internet connections that I want to connect.

I just realized it only has 1 wan port. Is there no other way to connect the 2nd internet connection?

Do I have to buy the peplink balance 30x?

You can use a USB-to-Ethernet adapter to add a 2nd Ethernet based WAN connection.