ObusForme Highback Backrest Support - Extra Tall Padded Seat Cushion and Lumbar Support Pillow, Portable Posture Support with Soft and Durable Foam

Those mesh chairs are garbage. You either buy a new chair or you buy something like a high back orbiforme to use with the chair. https://www.amazon.com/Obusforme-Highback-Backrest-Support-Black/dp/B005EJP0OS