Created the following API Function and trying to test it before deployment:

APIFunction[
{
"checkin"->"RawJSON",
"user"->"RawJSON",
"secret"->"String"
},
DatabinAdd[Databin["xxxxxxx"],<|
"Timestamp"->FromUnixTime[#checkin[["createdAt"]]],
"CheckinID"->#checkin[["id"]],
"Venue"->#checkin[["venue","name"]],
"Category"->#checkin[["venue","categories",1,"name"]],
"Location"->GeoPosition[{#checkin[["venue","location","lat"]],#checkin[["venue","location","lng"]]}],
"Shout"->#checkin[["shout"]]
|>
&]
,
"HTMLThemed"
]

The resulting item in the datadrop, though, is the top item in the attached list (the datadrop website only returns images, not text):