Or make one if you already have the components.
View attachment 141072
I'm assuming you live in a climate (Australia) where you don't need freeze protection, or else or can park within shelter.
Jack the weight off the tire, remove the valve core, and your garden hose pressure will fill the tire. Halt occasionally to bleed off air.
Note this homemade tool has the pin removed which pushes down on the (absent) valve core. No water would come out, if the pin were still installed.
Finish with the valve at 12:00 position (top) and leave airspace above that so the tire can still have some resiliency. Replace the valve core and air up to the minimum specified for that size tire.
If you always check tire pressure with the valve at the top, you can bleed a little air to clear the valve so you won't run water into your tire gauge.
I found that filling the tires made a large improvement in side-slope stability plus improved the traction for discing. But with my oversize tires, the excess weight required that I climb the grades in my orchard in a lower gear. After I installed the ROPS I reduced the tire fill to 50%.