Help with Elemente 2020 save in photo format Vertical 9:16

Can someone help me to make my video in Adobe Elemets (NOT PRO) 2020 to a Vertical video in 9:16 format......?

It wil not make me change the Frame size Horizontal 1920 - Vertical 1080

to the 9:16 format Horizontal 1080 - Vertical 1920!

I can not the the black sides to get away in adobe, even i have filmed it with phone Vertical.

If i try to save it in Mobil and Custom format, and i change it to 9:16, then the video get half size  :o(

Hope someone can help me and explain it simpel 🐵

Thx Johnnie