Transfer funds between accounts of different users (cross-business transfer) When to call this API
Call /transfer/external when the payer and payee belong to two different platform accounts
(different accountIds).
Example:
- Account A (a merchant) pays 500 USD to Account B (a personal user)
- A marketplace collects 100 EUR commission from the seller’s account and sends it to the marketplace’s own account
limits: if payer and payee account are crypto accounts ， support transfer between sub-wallet and master wallet（for the same currency）

if payer and payee account are infinity Accounts， support transfers between master merchant account and sub-merchant account/end-customer account (for the same currency)