SharePoint online "ReplaceAll" or "Substitute" flow syntax

Have a list with a multi-choice column and periodically need to change one or more of the choices.

• Column title is "Technology"
• It is a multiple choice column pulling multiple choice checkboxes from a Site Column
• I want to change one of the choices from 'TEST TECHNOLOGY 3' to 'TEST TECHNOLOGY 4'
• First I change in the site column, but that creates a list orphan that requires manual editing.
• Need a flow that can be edited and make all changes in the list.

A flow using ReplaceAll or Substitute looks simple, but I cannot seem to get the syntax correct. I created a "Get List" flow, successfully connected to the website and selected the list in question. Then entered the lines below in the function box. Have tried many variations. Does anyone here know a way to accomplish this?

    ReplaceAll('Technology','TEST TECHNOLOGY 3','TEST TECHNOLOGY 4')

    Substitute('Technology','TEST TECHNOLOGY 3','TEST TECHNOLOGY 4')