From the README:
Shape Key Transfer for Blender 2.93
Use this addon to easily transfer shape keys between meshes of different topology.
Place both the meshes at origin and overlap them at the location you want the destination mesh to copy shape keys of the source mesh.
This addon was initially created to copy shape keys from ManuelBastioniLab Character to other meshes, but can be used in any situation.
This addon is based on the code within this StackoverFlow post made by me.
The addon will be under Tools -> Shape Key Tools
You can exclude shape keys also.
Use Increment Radius to increase the number of vertices from the source mesh which affect the destination mesh.
When Use Closest Vertex is off it will average the locations of all nearby vertices within the Increment Radius.
Fewer vertices in the source mesh will make the operation run faster.
This tool is very useful to copy specific shape keys between meshes in Blender.