New Teams - Backgrounds folder

Hi everyone ,

im trying to put a lot images on the folder of "New Teams" that is  : "C:\Users\leomat\AppData\Local\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams\Backgrounds\Uploads" but there aren't the backgrounds . 
I saw that when i upload a background from Teams videocall the name became like this : "7fbae022-ba57-4b62-9ca5-43672eca5572" (UUID).

How can i put my background folder in one shot?

Thanks to everyone.