Base 7 portable, split database

Having had numerous problems with embedded databases, i now only work with split databases.
Libreoffice7 base portable only allows opening embedded hsql databases. How do it connect to my split database. Right clicking on the database name in explorer and selecting 'open with,… Portable base, opens the database but if trying to work with it, asks for the directory of the lacking java environnent.
Any suggestions ?