I have created a custom entity and added a main form for this.
When I am trying to edit the header for the main form, I am not able to find "High Density" header option as described in the below link:
https://docs.microsoft.com/en-us/power-apps/maker/model-driven-apps/form-designer-header-properties
Only option available for header is "Show Header Flyout".
Can you please if I need to make any changes in form setting to have this option.