Work won't supply proper chair

[Help987]

My work chairs are awful for back pain, can anyone recommend a brand or specific desk chair that can help support my back properly when doing up to 10 hours computer work a day? Really suffering with an awfully painful back.

We have desks that you can sit and then adjust for standing.
I alternate every hour but at the end of the day it’s hard on your back

My office and work from home chair are both from here:
https://www.mikeodwyerofficefurniture.co.uk/13-operator-office-chairs