I believe I just did this. I added the asset pack to a project. I opened the animation graph that came with the asset pack. In the lower right panel (default layout) is the asset manager where it shows all the animation sequences and any blends it may have. Right click the animation asset you want to have on the other compatible skeleton mesh. In that menu is the ‘make a copy for a different skeleton’ option. It will open a window that shows the skeletons available. Select the skeleton you wish to copy the anim asset to and click retarget. Once the action is completed the anim asset should be available in the desired skeleton’s asset management window.
Ps You may have to set the retargeting options for all the bones in both skeletons. This isn’t visible by default. To make it available check the option in the view. Then right click the newly available retargeting option column for a bone and select the 'recursively set all retargeting to animation.
Hope this helps 