Hi,
Hopefully you only need to do this for fields that you have created as changing a OOTB reference field to a string can cause huge problems. As that field could be being used in other scripts/business rules/flows/etc
In any case, one way to do it is the following:
Right click on field name "task"
Select configure dictionary
Change type from Reference to String
Result:
If this field is brand new and hasnt been populated before in any records then this is an okay solution.
If this field is populated already in the system by some records, you must be careful as you could lose data that was stored in this field as a reference.
In that case, you should create a duplicate field with the string type and run a background/fix script to copy the reference's display value (.getDisplayValue) into the text field
But as per your customers question - "Is this possible?", answer is yes
