post https://api.mintology.app/v1/custodial-wallets//exports/approve
IMPORTANT: Call from the back-end.
Export the Mintable wallet private key. This endpoint requires the request_id (which you got when calling 'Request to Export Mintable Wallet', and the OTP which was sent to the user by that endpoint (called code here).
This endpoint should always be called from your backend to prevent any potential spamming or exposing your private API key.