curl --request POST \
--url 'https://api.flashcat.cloud/calendar/event/upsert?app_key=' \
--header 'Content-Type: application/json' \
--data '
{
"cal_id": "<string>",
"summary": "<string>",
"is_off": true,
"start_at": "<string>",
"end_at": "<string>",
"event_id": "<string>",
"description": "<string>"
}
'