Please, no thoughts. I've done everything you've suggested already. I need to know how to do it, not how not to do it. The Home Advisor app is also asserting itself, though I don't even know if you can dial out on it. It's not just Firefox, it's my whole phone, even using my contacts. I need someone to answer that can help solve the problem. I am at my wit's end and out of patience with this. I've too many troubles right now to be patient with those answering that literally don't know how to fix this.
If you don't want people to suggest things you've already tried you need to tell us what you've already tried. We only know what you've written, nothing more. All of that should be so obvious that it shouldn't need saying. I want to give you the benefit of the doubt and assume that you are really better than your attitude here suggests.
Bear in mind also that there is more than one app called "Text Me" out there, so we can't even know for sure which app you have a problem with. Maybe someone else who has used this app will see the thread, but if they don't know which app it is that's trickier, so a Play Store link might help by removing any ambiguity.
So, first thing: did your stock dialer handle these links before you installed Text Me? It should, but if it didn't there is no way of making it do so (& if you don't know you also don't know whether it's possible). It would also help if you were clearer on what happens: your first post makes it sound like Text Me handles the intent automatically (i.e. behaving as a default app), while this one talks about something called Home Advisor offering to handle these as well (which is what happens if no default is set for that particular type of intent). If you are being offered options, is the stock dialer one of them? If not then clearing Text Me won't help. If going into Settings > Apps, finding Text Me and selecting "clear defaults" doesn't change anything, have you tried installing an additional dialer (which should force the system to ask again, since there is now a new app offering to handle the intent)? Even try using an alternate dialer, then either stick with that for this purpose or see whether you can return response to these links to the stock one (assuming it is capable).
If that doesn't work (i.e. Text Me keeps control of this intent regardless) maybe just check that it's not a Firefox thing by trying with a different browser. This shouldn't be the case, but just trying to work through all possibilities.
If clearing defaults doesn't work, a different dialer or browser changes nothing, there is nothing in Text Me's own settings that's telling it to take over such links, then a radical approach would be to back everything up and do a factory reset. Don't reinstall Text Me until you have checked this is working correctly without it. Then reinstall and test what happens. If the stock dialer does work, but Text Me takes over without asking or your preferences are ignored, then either Text Me is a rogue app or there is something wrong with your phone manufacturer's implementation of the operating system. In which case your options are to contact the developers of Text Me, contact the phone manufacturer, or decide which is more important, having Text Me or having the problem it brings.
If there's no solution and you can't give this thing up, a workaround would be to copy the number and paste that into the stock dialer rather than click on the link: clumsier, sure, but it should work.
That's covered everything that I can think of. Good luck.
P.S. I've been here a decade without using my ignore list, but if you are unhappy with my providing suggestions rather than a definite answer based on the incomplete information you have provided, and feel that you should express this as you have before, it won't bother me at all to make an exception.