Stutter at serious conversations only

Stutter at serious conversations only I stutter during interviews, presentations, and Zoom classes especially when I'm nervous or under pressure. How do others manage or reduce stuttering in serious situations like these? I'm usually fine in casual conversations, but when it comes to formal speaking like interviews or public speaking I start stuttering a lot more. It really affects my confidence. I'd love to hear how others deal with this or what has helped you improve.