I found two parts of the codelab description that might possibly be errors and report them.
First look at the description in the section on Writing data to Proto DataStore in codelab
I'm not sure, but perhaps userPreferencesStore.updateData() is correct for the red line in the image, not dataStore.updateData().
Second, the sample code in the image above is probably incorrect when the language is not English in codelab.
For example, look at the sample code when the codelab language is Japanese

As well as sample code for the English version,
dataStore..updateData { ...
The above should be modified as follows
userPreferencesStore.updateData { ...