Have your Texas Parks and Recreation department provide you with a list of licensed applicators.

Texas is not alone. I don't know of any state where it is not restricted.

I would hire someone to apply it as you will regret it if you don't. (leaving trash fish in the pond)

In most states you can apply it yourself, and purchase it yourself if you take a short course and pass a test. However it's typically only offered once a year and in my case for just one application it would be cheaper just to hire someone. I checked it out.

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.