Is it normal to fart on command?
Depends.It depends
Yes, some people can fart on command by tightening or relaxing muscles and pushing out gas that’s already there. You can’t make gas appear from nowhere, though, and not everyone can do it.
If there’s gas ready to go, you may be able to release it by changing your posture or using your abdominal and pelvic-floor muscles. It’s a body-control trick, not a special talent everyone has—and sometimes the gas has other plans about when to show up.
So it’s normal if you can do it, and normal if you can’t. Just don’t strain hard to force it; your insides aren’t a party trick.