Solved it!
In the body I simply needed to include the following:
{
“active”: true,
“identifier”: “https://kf.kobotoolbox.org/#/forms/aGNiRRxVx9Cbb7zqQtohiY”,
“version_id”: “vEf5cVkESUgLSNXuvwNjao”
}
Inferred from this thread
Hopefully this helps others! The KoboToolbox documentation could definitely do with more detail.