Custom video Settings.

First, click on 'Settings' on the left-side menu. Alternatively, in the Dashboard page, navigate to the 'App Setup' section and click on the 'Customize Setting' option. On the right side, you will see the 'Go to Settings' button. Click on it, and it will take you to the Under Construction settings page.

In the 'Template Customizations' section, if you want to add a custom video to the Under Construction Coming Soon page, you can find the last option. Check the radio button to select 'Custom video upload'.

When you select 'Custom video upload,' you'll see the 'Upload visual' button. Click on it to upload your own video.

After that, click the 'Save' button, and your changes will be visible in your store.