Here's the actual text:
capitol.texas.gov/tlodocs/88R/billtext/html/SB01029I.htm
Reading through it, the main points are liability, and coverage in state plans.
If you do offer it:
STRICT LIABILITY FOR HEALTH COVERAGE. A health benefit plan issuer is strictly liable to a patient for the patient's medical, mental health, and pharmaceutical costs, including costs associated with reversing a gender modification procedure or treatment, incurred for the life of the patient as a result of a gender modification procedure or treatment covered by the issuer's plan.
Plus also liability for the physician or health care provider.
The actual ban is on certain forms of insurance from covering it - there's a list of "chapter XXX" health coverage plans, including Medicaid, so presumably these are ones getting some sort of state subsidy. They are not allowed to cover it in the first place.
So you can do it, but it mustn't be state-funded, and if you do you're liable.
I think there's a particular issue in the US that it's very, very hard to sue doctors for malpractice, due to some changes in the last decade or so, following some previous waves of successful group claims, and subsequent health industry lobbying. This seems to be trying to punch through that - in particular US detransitioners have said that they can't do anything more than 1 year after treatment, because there's a tight time limit.