Dashboard - time format

Hi folks!!
I'm not able to write the edit text input node, mode "time picker" in format hours-minutes-seconds (by default it is hours-minutes).
I think I'd modify the (which??) configuration file.
Thanks for helping me..
Bye.

The text input as time input just uses the html5 input type. How it is rendered is down to your browser.

Good.
And thanks.
I've got chrome, could you show me the way?

it is whatever your browser shows. eg see https://www.w3schools.com/html/tryit.asp?filename=tryhtml_input_time