I'd tell you to do this exercise at the office, but while this wouldn't take more than a few minutes, it'd be really weird if you just unrolled your yoga mat next to your desk and started exercising. .
Let's just say that people will stare 😳 (On the other hand you would claim the Posture Pioneer title 🏆 of the office, so you may want to consider setting a posture health example for everyone.) .
You could do this as soon as you get home instead. After a day of sitting 8+ hours it'll feel so good! Or you could make this part of your bedtime or morning routine. Or you could try multiple of those and see what works best.
For now, meet the best posture exercise: https://fitnessreloaded.com/best-posture-exercise-hunchback-kyphosis-slouching-too-much/