nomebig2: I am not acting as a consultant but simply using what I consider common sense. I cannot find any peer-reviewed literature on the use of Botox for post-Covid voice change. What I did find was that Botox routinely weakens the muscles of the larynx (voice box). I am not clear whether or not you understood the gist of my previous reply:

"In other words, Botox is used for spasmodic laryngitis, and if you did not have this then the Botox may have weakened the muscles near the vocal cords to cause the whispery voice you now have."

Since that is a possibility, then why would you consider another Botox injection and possibly add further insult?? My suggestion, once again, is to find a physician with a particular focus on COVID-19 and get a consultation before doing anything. I provided you pdfs of the peer-reviewed papers on voice change 2° COVID-19. Those papers have the email address of the corresponding author. Stongly suggest you email each of those physicians and in a few sentences tell them your story & ask them for any suggstions they may have. That's the smart thing to do-- at least in my opinion as a physician x 6 decades. And discuss this with key people in your circle of family and friends and see what the consensus is.
Stephen B. Strum, MD, FACP