This is no recommendation, but more a hint to find useful resources.
Well there seem to be some free resources.
First the limited Free GTO wizzard account, but its free.
Then there is a software on GitHub called TexasSolver but IDK how good this masterpiece is.
There is another free web based postflop solver called WASM Postflop which has also a github fork for a desktop application called desktop postflop.
This is no longer under development and there are no updates or fixes available.
There is another Solver called PocketSolver, available as Webservice or as downloadable Application for Windows, MacOS, IOS and Android.
Best is to use Google for searching these resources and perhaps some more.