just jump everytime you hit the ground, the exact frame you touch the ground.. jump then strafe left to right and left to right and keep going until your speed increases
When you want to play a real challenge you should play with traditional weapons... This is not even a challenge... The machine gun is very powerful and any normal player can win it even at the expert level... You look good and have some skill so Play solo challenges with real weapons... but good job anyway 👍🏻