when I put phone in box it still moves around

Check the illustrations:

"Lift the cardboard insert from the shipping box

and

place your Apple Watch, iPhone, or Android into the insert with the screen facing up.

Do not include multiple items in the same box"

The "Related;ated Article" above your question:

says:

"Lift the cardboard insert from the shipping box and place your Apple Watch, iPhone, or Android into the insert with the screen facing up. Do not include multiple items in the same box"

The article has illustrations showing how to make the device secure.

same, the phone is inserted into the box but pressing gently on the insert doesn't really secure the phone.

"Lightly press down on the cardboard insert to secure your device."

unless I'm missing something in this kit the phone just slides around..