curl --request POST \
  --url https://mag3nt.com/api/mpp/session \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "card_id": "<string>",
  "card_token": "<string>",
  "merchant": "<string>"
}
'

{
  "session_id": "<string>"
}