MITP (MUART) Mitsubishi coding question with MHK2

I am trying to add in global array and temp lamba codes to align the temp in home assistant to that of the MHK2 using the template off https://muart-group.github.io/user/configuration/useful-snippets#use-mitsubishi-temperature-conversion. It tends to be off a degree or so at the moment.

I have not been able to get the code to work as when I go to install the .yaml I keep getting an error code. Does anyone have an example of this working correctly? Thanks!