To import from MacPass, you must export your records from there first.
Click File > Export as XML.
Name the file and click Save.
Log into Keeper's web vault at https://keepersecurity.com/vault/
Click on your account email in the upper right-hand corner.
Click on Settings > Import.
Choose MacPass from the list.
Drag the exported file into the target window "Drop a File Here"
Use the drop-down menu in each column to map to a Keeper field.
Click on Import.