Keep your torso straight and stick your hips out

[Summary]
In type 2 of standing front flip, flexing our hip-joint and swing the upper body forward and get rotation.
On the other hand, in type 1 we push the ground by extending our knees and hip-joint, so we cannot help swinging upper body backward.
You should straighten your upper body up to prevent from rotating backward.
And to do this, look forward when takeoff.

He sticks his hips and chest out and his torso is straightened, not hollow before takeoff.

[Details and Theory]

–  Prevent from rotating backward –

If you swing your upper body backward, you will get backward rotation. Hence, you have to minimize the backward swing.
Having said that, you must open your waist. To accomplish that trade-off purpose, you should open your waist from the posture with your upper body straightened up not pike.
To stretch up your waist, at the moment of taking off, your back should be little rounded.