curl --request POST \
  --url https://haunt.gg/api/imagehost/upload \
  --header 'Content-Type: multipart/form-data' \
  --form 'key=<string>' \
  --form file=@example-file

{
  "success": true,
  "url": "<string>",
  "filename": "<string>",
  "size": 123,
  "type": "<string>"
}