curl --location --request POST 'https://api.openai.com/v1/threads/thread_abc123/messages/msg_abc123' \
--header 'Authorization: Bearer $OPENAI_API_KEY' \
--header 'OpenAI-Beta;' \
--header 'Content-Type: application/json' \
--data-raw '{
"metadata": "string"
}'
{
"metadata": {
"modified": "string",
"user": "string"
}
}