Media Box is missing in Lesson Setting

Hi
I use EiKRA Theme (https://themeforest.net/item/eikra-education-wordpress-theme/20950897). The media box used to be there so I could paste the embed codes from Youtube and Linked in but it is not there anymore.

You can see the problem in the following link:
https://drive.google.com/file/d/1nl4sfkUstvYbQKRpRWye2awdTTCkmJTq/view?usp=sharing

The page I need help with: [log in to see the link]