@Denise253 I'm sure as a realtor you know that every government gets it's cut, you've been renting since at least 2017, have you paid no taxes in that time? Every city is different, you should certainly follow the CCRs and the ordinances for your location. In Austin there is City, County, Tourism Development & State taxes, Austin hosts are also supposed to get a license from the city and be legal with their HOA. (I'm outside city limits so I thankfully do not have to mess with any of that.) If you were here, the city would be asking you to go backwards and pay them all the taxes you've skipped since 2017 and probably fines on top to boot. If Dallas is trying to get a lid on STR you may want to go back and find out what your rules are (were) and get compliant or close shop and hope they go for bigger fish. Or you can follow up with whoever sent you a letter and beg for forgiveness and leniency if you get proper procedures set in place going forward. Good luck!
PS you've surely reported all your income to the IRS too, right?