Generate a temporary KYC verification link for a sub-account via the V4 API.
The public WhiteBIT API key.
Base64-encoded JSON request body.
HMAC-SHA512 signature of the payload, hex-encoded. Computed as hex(HMAC-SHA512(payload, api_secret)).
Sub-account external ID. Must belong to the authenticated main account.
"8e667b4a-0b71-4988-8af5-9474dbfaeb51"