This is ELiGE's known ergonomic gear:

Lumbar:
Everlasting Comfort 100% Pure Memory Foam Back Cushion - Lumbar Support Pillow for Office, Car and Chair, Standard, Black

Wrist:
SubZERO Gaming Wrist Rest/Pad for Keyboards

Stretches for gaming:

Dr. Levi's wrist and hand exercises for gamers:
https://www.youtube.com/watch?v=wYGfDCGrJ4A&t=390s

Athlean's guide to correcting posture:
https://www.youtube.com/watch?v=g-7ZWPCWv0U