Set the Sync Marker for the foot

If your animation has root motion, you can use convenient methods

First, select Animation Data Modifiers

Then click on Add Modifier on the right side and select SyncMarkerAnimModifier

Then click on Apple All Modifiers

This will automatically set the Sync Marker

If your animation does not have a root motion, manually add it

Under Notify in the animation, right-click Add Sync Markers, then select Existing Sync Markers, and then select L or R based on the left and right feet