I am planning to get underarm Botox because of hyperhidrosis. How effective is it?

Every summer, I sweat excessively in my underarms, so I cannot wear gray or colored clothes at all. My hands sweat a lot too. I have tried applying deodorant and over-the-counter antiperspirants, but my skin stings and itches so much due to side effects that I can't use them. That is why I am considering getting underarm hyperhidrosis Botox (sweat Botox) at Maypure, and I am writing to inquire about when the effects usually appear and how long they last. I would like to know if the sweating really decreases significantly after the injection, and how much pain is involved in the procedure. I am also curious if it will be embarrassing since it is the underarm area, and how long the procedure takes. I desperately want to spend this summer comfortably, so I would be very grateful if you could also answer if there are any precautions I should take after the procedure (such as avoiding saunas or exercising).