I liked the original design of these and the original creator even provided Fusion360 file but I took inspiration from this QR Code Sign to use TinkerCAD for easy customization.
Simply open TinkerCAD, un-group the secondary text “Inland”, input your value, resize (if needed), regroup, and export.
https://www.tinkercad.com/things/9Y5OTGMK0IW
I am also including my STL in case all you need is a copy of what I have here.
The author remixed this model.