office365 – Dropdown / LookUp on PowerApps

Since a few days, I created a form in PowerApps. I have a main field "Code" that, when typing, via a list in SharePoint, returns the user name, position, department, and so on.

For these text fields, I use the following line:
LookUp (BBDD; Code = DataCardValue1.Text; & # 39; First Name & Last Name)

The problem is that with DropDown it does not work and I do not select them when I enter the corresponding code.

I appreciate all possible help.