Compile Error related to TextProperty

Can someone help me identify how to solve this error “member GetAltitudeText unable to bind TextProperty, unsupported type”? For context, I am following a drone tutorial on youtube (https://www.youtube.com/watch?v=5sSbFJ13uj4) and am at the 17:13 time stamp. When I compile I get the previously stated error.

Attached are screenshots of the error and “Get Altitude Text”

Error: