Unfortunately this isn't as straightforward as it should be but there are some helpful scripts out there that can automate some of this process for you. You will need some development skills to take advantage of these.
One such script is available here:
Instructions for the conversion process:
1. Create a Keepass file (recommendation: use an empty file)
1. Tell Enpass to export its database to a JSON file
1. Run the program
Jörg developed this script when we was trying to migrate over from Enpass. This will convert an Enpass exported JSON file to a KeePass database. You can learn more at the above link. Note there may be some slight imperfections in the process, and caveats apply, always backup your data before hand.