Try doing abdominal exercises that includes tummy tucks, curls, leg raises. Wear the abdominal belt but solely wearing the belt would not help so exercises are a must.
Keep a watch on your diet too.
Next Steps
Visit a women health physiotherapist for better layout of exercise program. You can also consult a dietician for diet information.
Health Tips
Do not just try random exercises without any supervision/consultation as you may not be able to figure what level of exercise you require that may land you in an unexpected muscloskeletal problem such as muscle spasm (catch).