Add the animation to a new track above your footage and set the composite mode to Overlay or use the 3D Keyer in the Color tab to remove backgrounds.

Sites like LenosTube provide downloadable packs in formats like .mov .

You can find professional, "clean" subscribe animations on several free platforms:

Import your video and the animation file onto separate tracks. Use the Ultra Key effect to select and remove the green background.

You can use Canva or ProFounder to create animations that include your own channel name and logo before downloading them as MP4 files. 2. Implementation in Video Editors