How did you obtain BRINSUPRI?

It seems many on this forum are taking Brinsupri. Assuming you are on Medicare I would really appreciate hearing how you got it approved. I know it currently requires a PA (prior authorization from your Dr). So the question is which Insurance approved it? Which Part D plan?
I never signed up for Part D so I must do that NOW so that my Dr can submit a PA to them. Brinsupri is not on any formulary lists and doubtful that it will be in 2026. So selecting a Part D plan in hopes that they will approve it, is just a gamble. In my area I have Wellcare, Silver Script, Humana, Medicare Blue and Health Spring (used to be Cigna) to choose from. Did you have success with any of those?
One person suggested that they “have to approve it” if a PA is submitted and there are no other choices etc. but I have learned that is not true.
My Dr really wants me to try it for my serious situation. Any insight would be greatly appreciated.