Hello @dm_e, my apologies for the time to response on this.
To map the JSON of an Unstructured Event please select the variable where it is stored in the mapping toolbox. Select the Unstructured Event category on the lefthand side and then check the box for “User Defined Context”. If you use this method you will not need the ue_px extra outer self-describing JSON for unstructured event only the outer self-describing JSON the actual event.
To get your data in Base64 please select a variable which will have a value of true in the mapping toolbox. Select the Tracker category on the lefthand side and then check the box for “Use Encode Base 64”. This will send any self-describing events and custom contexts sent to the tracker in base64.
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