Video treatments work differently than the traditional static treatments in Marpipe. Instead of assigning different treatments to your Meta ads you will be adjusting the settings on the ad in Meta in order for the video treatment to be automatically used instead of other media.
Here is what to do
Prerequisite: You have video DPA designs published into your video treatment and your video treatment is in an output feed that is actively connected to a Meta Catalog.
Step 1: Create an ad that is using your catalog as the creative source in Meta.
Step 2: Go to Advantage+ Enhancements and click edit.
Step 3: Turn on Dynamic Media and then click customize.
Step 4: In the customize settings you may see an option to prefer video if it's available. Make sure that it is turned on if you see it.
Step 5: Save the enhancements settings and then publish your ad.
The ad should now use videos if they are available and you should see the video present in most of the ad placement previews.