Create a gateway with that IP address. Create default route to that gateway. It's just one more layer of abstraction enabling to give the gateway IP addresses meaningful names.
Can you ping the gateway .229 from your OPNsense? If not you need to contact your ISP about the correct configuration.HTH,Patrick
Just to point out.... When you mask the first 2 octets in one post, then mask the last 2 octets in another, it's pretty easy to put them together.