How many minutes of exercise a day is needed to effectively lose belly fat?

I started a diet because my belly fat is my biggest concern, but I am wondering how much time I need to exercise to see results. I am busy with work on weekdays, so I can only exercise for about 30 to 40 minutes a day. I am worried if it is possible to lose belly fat with this amount of time.

Currently, I am doing aerobic exercises such as walking and stationary cycling, and occasionally I also do strength training like planks and squats. However, some people around me say that I need to exercise for more than an hour a day to lose belly fat, while others say that intensity is more important than duration, so I am confused about which method is more effective.

I am also wondering if it is better to exercise every day, or if exercising consistently about 4 to 5 days a week is sufficient. I would like to know if managing my diet along with my workouts helps with belly fat loss, even if the exercise time is short, and what the optimal ratio of cardio to strength training is.