Any treatment for sweating?

Hey guys,
My friend has been suffering from extreme armpit sweat. She says it happens all the time, and it gets worse when she gets nervous. I have also seen she keep trying different deodorants. Sometimes she tries powder treatment, and she still keeps searching for a permanent solution for this. She just wants to stop her armpits from producing sweat.
Sometimes this affecting her both mentally and emotionally. So that’s why I decided to find some help for her. Is there any permanent solution for this? I have heard about taking Botox treatment. Is that an effective treatment for excessive sweating? If so, how does it work? I would like to hear your recommendations or experiences.
Thanks!