Irving Drinkwine writes:

I have a wheelbarrow that has a tubeless tire. The tire went flat at
some point and sat that way for a while. Now the tire is out of shape
and I cannot get it to hold air.
Any suggestions on how to fix this short of buying a new tire/wb?
Put a tube in it show how perhaps?

Others have given advise about repair.
In my case, I couldn't get any of those methods to work.

I called the manufacturer for instructions.
They took my address and sent me a free replacement.
Turns out the tire has a lifetime warranty.
Bought the wheelbarrow at HD.