How to set select.select_option vaue from the select option

This might be a very dump question but I’m struggling to set the value of a select.select_option from the entity’s list of available options.

The entity:
{{ state_attr(‘select.neff_ID_bsh_common_option_startinrelative’, ‘options’) }}
or
states[variables.var_startinrelative_slct_entity].attributes.options (in custom:button-card)

Has the following options:
[‘0:00’, ‘0:30’, ‘1:00’, ‘1:30’, ‘2:00’, ‘2:30’, ‘3:00’, ‘3:30’, ‘4:00’, ‘4:30’, ‘5:00’, ‘5:30’, ‘6:00’, ‘6:30’, ‘7:00’, ‘7:30’, ‘8:00’, ‘8:30’, ‘9:00’, ‘9:30’, ‘10:00’, ‘10:30’, ‘11:00’, ‘11:30’, ‘12:00’, ‘12:30’, ‘13:00’, ‘13:30’, ‘14:00’, ‘14:30’, ‘15:00’, ‘15:30’, ‘16:00’, ‘16:30’, ‘17:00’, ‘17:30’, ‘18:00’, ‘18:30’, ‘19:00’, ‘19:30’, ‘20:00’, ‘20:30’, ‘21:00’, ‘21:30’, ‘22:00’, ‘22:30’, ‘23:00’, ‘23:30’, ‘24:00’]

In the template I would like the “action: → service_data: → option:” to be the selected element of the dropdown list of available options.

tap_action:
  action: "call-service"
  service: "select.select_option"
  service_data:
    entity_id: "[[[ return variables.var_startinrelative_slct_entity ]]]"
    option: "the selected item from 'states[variables.var_startinrelative_slct_entity].attributes.options'"
  target:
    entity_id: "[[[ return variables.var_startinrelative_slct_entity ]]]"

Many thanks!

Better to ask in this card’s thread.

Ok, many thanks!