I'm however really struggling to understand how to use the 'dictionary' object together with 'Instant Games' and 'get player data / set player data'.
There don't seem to be any options that allow me to link the 2 together.
You have literally been told how to use the Dictionary object with Instant Games twice in the same thread(JSON) AND linked to the Dictionary documentation which explains the expression for saving/loading a Dictionary as JSON.
To Save Data:
Condition: Whatever condition you want
Action: Instant Games>Set Player Data>Dictionary.AsJSON
To Load Data:
Condition: Whatever condition you want
Instant Games>Load Player Data
Instant Games>On Loaded Player Data>Dictionary>Load From JSON string>InstantGames.PlayerData