curl --location --request POST '/send_flash_msg' \
--header 'Content-Type: application/json' \
--data-raw '{
"fileset_id": "set_123",
"user_id": "123456789"
}'{
"status": "ok",
"retcode": 0,
"data": {
"message_id": 123456
},
"message": "",
"wording": ""
}