Is it possible for the form to have a mixture of pre-defined values, and a value which a user can enter?

[Wee_Chin_Lim]

Hi everyone!
I am trying to run an expression for a form in a Deliveries Table, there are three “Delivery Type” options, “Door Delivery”, “Pick-up at Collection Point” and “Pick-up at Store” and each delivery type will result in a different “Address”.

I currently have the App Formula set as below in my Address Column in Deliveries Table.
"
IF([Delivery Type] = “Pick-up at Collection Point”, “xxx”, " ")
OR(
IF([Delivery Type] = “Pick-up at Store”, “yyy”, " ")
)

"
I was wondering if it is possible when “Delivery Type” = Door Delivery, users will be able to add their own address into the form.

At the same time, I was wondering if it’s possible if there’s an expression for where if “Delivery Type” = Pick-up at Collection Point, the form will show an enum of different addresses?

If i am unclear on anything, let me know! I’ll do my best to explain clearer.