Can I use geo blocking for a specific NAT rule?

I'm using a Sophos SG230 with the latest version of UTM 9.

I have a NAT rule routing https traffic hitting a specific external IP to of our servers.  Currently it allows traffic from any IP address through since it could be accessed by users from their home PCs, phones etc.  However I would like to lock it down as much as possible since the server is now being hit with a lot of attempted connections from known compromised IP addresses.

I don't really want to turn on geo blocking in the firewall settings since that blocks all traffic by default and there would be too many exceptions to set up.

Is there a way I can add to the NAT rule that it should only apply to UK addresses rather than using the "any" selector?