Multi- Dynamic DNS for OpenVPN setup

pfsense version = 2.5.1

So have 2 ISPs each with 1 static IP let’s say ISP1 = 120.x.x.x and ISP2= 54.x.x.x and then we’ve used for free dynamic DNS and it worked if we only use in this case ISP1 for openVPN setup for our pfsense and then convert ISP1 static IP to dynamic DNS.

But then were having a problem to setup Multi-DDNS maybe some tried this setup?

We never use DDNS with out clients, might want to ask this in the pfsense forums