How can an IT professional with minimal physical activity lose weight?

Hello doctor,

I am 25 years old IT professional. I have been working for more than six years and have been involved only in minimal physical activities. Recently due to COVID, my work shifted to remote mode, and my level of physical activity has dropped even more. As a result, I have constantly been gaining weight. I have gained 17 pounds in the past year. I tried various weight-loss strategies like the keto diet, paleo diet, completely avoiding rice, etc. But there is no result. Since my working time is more than 10 hours per day, I cannot be actively involved in any sports or exercises. Kindly help me to reduce my weight.