You cannot define the valueType in the CSV import for option sets. Set the valueType using the UI or API before or after importing your options.
When importing option sets and options via CSV in DHIS2, there is no direct way to define the valueType in the CSV file itself. The CSV import format supports columns like optionsetname, optionsetuid, optionsetcode, optionname, optionuid, and optioncode, but does not include a column for valueType.
If you need to set the valueType for an option set, you should do this either before or after the CSV import, using the DHIS2 UI or by editing the option set via the API or a JSON metadata import.
check this out (Metadata Imports (Option Sets) - Value Type) seems to be talking abour the same issue!