Follow these steps if you want to use your own logo:
Please note: section 1+2 explains how to add a logo to the assets, 3+4 are talking about adding your logo to your video using the composer.
1. Enter the left menu and select "Branding"
2. Add your own logo by clicking on the "Plus" button.
3. Enter your video, click on the 3 dots on the small video and choose "Style your video".
4. Choose "Logo" and click on "Add logo".
5. Choose where you want your logo to be placed.