curl --request POST \
  --url https://api.docs.magicblock.app/private/tx/prepare-withdrawal \
  --header 'Content-Type: application/json' \
  --data '
{
  "user": "<string>",
  "mint": "<string>",
  "endpoint_url": "<string>"
}
'

{
  "transaction": "<string>",
  "message": "Transaction created successfully"
}