How to lose lower belly fat?

Eat fewer calories than your body uses in a day, and lift heavy (for you) weights.

That's the simplistic answer.

In reality, you normally cannot gain muscle and lose fat at the same time. But I suspect losing fat while lifting heavy will get you the results you are looking for.

There is no way to target an area of fat. This is a myth that marketing firms use to keep you spending money.

The ONLY way to lose the fat you want in an area you want is to lose weight(fat) in general. your body and genetics will take care of the rest. Typically lower abdominal fat is some of the last to go (before 6 pack shows).

Where your body puts it on first, is where it will take it off last.