Your network and firewall configurations both appear to be fine for what you want to achieve, but the underlying problem might be outside your control: your OpenWRT router does not have a public IP address. This means that at least one upstream device will also have to be configured, not just your router.
If you have sufficient access to that device to configure it, you may be able to set up the necessary port-forwarding to your OpenWRT router for WireGuard to work. If not, then you'll have to talk to your ISP to find out what can be done to allow WireGuard inbound. Your ISP might permit the necessary ports to be opened, or might even allocate you a public IP address.
Another forum member had a similar issue to yours (private IP address, unable to get inbound traffic working). I knocked up a quick diagram to illustrate the cause of the issue: How to port forward to my Jellyfin server? - #46 by iplaywithtoys