The OCTAPAD SPD-20PRO cannot load the SPD-20 data as-is.
If you want to recreate the patches on the SPD-20 that you created with the SPD-20PRO, create a kit using the same instruments as the SPD-20.
NOTE: OCTAPAD SPD-20PRO is not available in all regions. Please check with your local distributor for more information. https://www.roland.com/global/international/