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In your draft email.
For each additional field, you will need to place the name of the mergo Mergo field Header in merge brackets {{ }} and specify the object under the Header in the Google Sheet
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A Header for Instrument was created, and placed in Merge brackets in the Google Draft message.
Piano was specified for Billy as the object under the Instrument Header in the Google Sheet
Another header for Food was created and placed in Merge brackets in the Google Draft message
Piano was specified for Billy as the object under the Food Header in the Google Sheet
The finished message would appear in screenshot below