dynamic dropdown

I have a database record "einsteige_ort" with following 1 to 8 values:

["Ruetihof","Gebenstorf","Trafo","Schademuehle","Eurobus","Lauffohr","Bahnhof","X"] that I want to populate a dropdown field "zusteige_ort"

I have a php96 like that:

$options =  ['value' => $this->data("einsteige_ort"), 'text' => $this->data("einsteige_ort") ];return $options;

and the Dynamic Options set as {var:php96}.

It does show an empty field. How to solve?

The FAQ "Dynamic options for dropdown and multi selection fields does not gives me enough information. Could you help?

BDW: a read data option is indeed included.