Texas doe not have a state income tax. What are you trying to do? What are you trying to enter? Some screens will not include Texas as a choice since there is no state income tax in TX.
If for box 15 on a W-2, then leave boxes 15, 16, and 17 entirely blank.
In the personal info section where it asks if you earned money in another state, there is an instruction to answer no if you earned money in TX (and a handful of other states without an income tax).
The general rule is: your report all your income on your home state return, even the income earned out of state. You file a non-resident state return for the state you worked in and pay tax to that state. Your home state will give you a credit, or partial credit, for what you paid the non-resident state.
Since TX does not have an income tax, you do not have a non-resident return to file. But you still have to pay tax on that income to your home state. In other words, having worked in a state without an income tax does not get you out of paying state tax on that income, to your home state.