How to communicate with wireless printer on another subnet?

I have successfully setup an admin/management VLAN on my OpenWrt router with firewall zone forwarding to the LAN interface so that for example, a computer connected to the admin VLAN can connect the LAN resources etc. I have also setup access to the admin VLAN from certain LAN devices through the use of traffic rules and specific MAC addresses.

I'm now trying to connect to a HP Wireless Printer that is on the LAN from the admin VLAN. Unfortunately the HP Smart app doesn't support different subnets hence I can't see the printer in the app. However, there doesn’t seem to be any problem with being able to access the printer’s admin GUI webpage and ping the IP address.

Is there anyway of being able to connect to the printer from a device on a different subnet? Will static routes help at all, although I have never used static routes nor would I know where to start, however, I do understand the IPv4 protocol fairly well.

No, static routes are not going to help, there is no routing issue. The problem is that the mobile app is expecting to detect or communicate with the printer over broadcasts.
Have a look here.

I shall definitely have a look at that. It seems interesting that many people are making isolating IoT into their own VLANs.

on the hp smart pc it does not work, but on the mobile app it does, create in the Router, not in openwrt a static route type of the ip where you want to access the ip of the openwrt Router of the domain where the mobile is connected

but on the pc you can download the original application with the drivers that were used before hp smart and with what was said above it works perfectly by manually indicating the new ip of the printer