How do I choose which field(s) is(are) displayed in a dropdown related to a reference field

[Service_Tmr]

Hi All,
I have one Google sheet, with four internal sheets.
The sheets of concern are

1. “Technicians”, main fields being “tech_id” and “tech_name”.
2. “DailySheets”, fields of concern are “tech_id” and “tech_name”.

“tech_id” in “DailySheets” is a reference into the “Technicians” sheet.

On the “DailySheets” form, I want a dropdown of the “tech_id” field to display the “tech_id” information. Right now it displays the “tech_name”
On the next row I want the “tech_name” to be displayed. ( fixed using “LOOKUP” command)

What is actually happening is that the “tech_id” drop down displays the “tech_name” for selection and does not store the “tech_id” value.

How can I change the dropdown field information and store the “tech_id” values to the “DailySheets” form?