How many denials before insurance approved Botox?

Just curious what others experiences are. My neurologist started administering the 31 injections as "samples" back in September. Insurance always comes back with a denial and request for more proof of other trials. Same thing happened in December and when I had my 6-week check-up last week, they told me it still hadn't gone through and to expect another appeal process for my next session in early March - which will be my third round of injections. The request is always to try this med and that med and prove everything else under the sun isn't working when between the injections and Qulipta, I'm down from 19 a month to 2-3, so that combo is working. I have tried Nurtec and it didn't work. I'm also on sumatriptan for abortive purposes, and also tried an antidepressant, the name escapes me now, but that gave so many side effects that we stopped after a month. There are a couple of others he's mentioned that I cannot go on due to my recent history with kidney stones. So for those of you who had your neuro advocate for botox and eventually got insurance approval, how long did it take before they admitted the doctor knows best and paid the friggin bill? In case it's relevant, I have BCBS PPO through my husband's employer.