Upsert contact
Use the current HighLevel API documentation and avoid new V1 API-key based work. HighLevel notes V1 end-of-support, so new production work should use the newer private integration path.
{
"email": "jamie@example.com",
"phone": "+15555550123",
"firstName": "Jamie",
"lastName": "Lee",
"source": "InstaChime"
}