Hello!
Get yourself checked by your primary surgeon.
If the site of operation is fine and also the wound and scar has healed as desired start walking and jogging in a slow and progressive way.
There are many exercises in sitting and sleeping posture which you can learn near a physiotherapist and practice.
Do not do any exercises which increase your abdominal pressure.
Take care!
My opinion is those belts don't work! First ask your MD if it's ok to use.