Import CALC spreadsheet .dbf greyed out

I am trying to import a calc spreadsheet into base. According to instructions I saved the sheet as dbase, UTF8.
Then I start a new Database, “connect to an existing database”. Select “dbase” and then the folder where the dbf file is stored. The file is listed as .dbf but greyed out.
Why? Is there a step I am missing?

Libreoffice 24.2.7.2, Linux Mint

depending if you really want to dig into the specific dbf issue.
but it’s far from mandatory to “import” from Calc.

Importing and Exporting Data in Base
You can open a *.dbf dBASE file or many other file types.

dBase is a database in a directory. Each dbf represents one database table. dbf is NOT a spreadsheet format. Spreadsheet applications may damage dbf files.

menu:File>New>Database…
Connect to existing database of type “dBase”.
Specify the directory where your dbf is stored (possibly with other dbfs).
Check “Register database”
Save the database document.

If the file used to be a spreadsheet, it is very likely to have inconsistent data.

The .dbf is not “the database” but one table of the simulated database.

No. You went one step to far to select the database. As Villeroy already wrote: You need to select the folder, not the single .dbf-File.