This should be handled by the medical boards of each state. Prior to retiring I could not see a patient via telehealth in Texas unless I was licensed there. My snowbirds would have to see me and get enough refills prior to heading south. Texas pharmacies would fill valid scripts that were transferred from another state. Savy patients would figure out I could not verify their location so they would say they were at home. Some were bright enough to put their kitchen as their background on the video.
How is Paxton going to enforce this, doubt if New York would extradite a physician.

Paxton hopes to invoke fear. Fear of providing care, or seeking care is just as effective as the actual ban.