It’s very hard to do these 2 things simulataneously
Really, this comes down to nutrition, as it almost always does.
If you want to lose belly fat, you need to be in a calorie deficit, so ingesting fewer calories than you use each day. To gain muscle, well, the opposite applies-you need to be taking in slightly more calories (and also importantly the right kind of calories) than you use each day.
Maybe take a read of my reply to another post below
