Flutterwave Test Transfer to Bank Account

Question

I am trying to test the setup to send money from Flutterwave account to MobileMoney using RubySDK in UGX currency to a Uganda bank account. My current understanding of the process is that -

1. Get the account bank from using "Get All Banks" API - https://developer.flutterwave.com/reference/endpoints/banks/#get-all-banks

2. Get destination branch code using "Get Branch Code" API - https://developer.flutterwave.com/reference/endpoints/banks/#get-bank-branches

3. Add the beneficiary using "Create a Transfer Beneficiary" API - https://developer.flutterwave.com/reference/endpoints/beneficiaries

4. Use the data collected in first 3 steps along with account number and amount to call the Transfer API.

Firstly, please let me know if there is a gap in my understanding.

Secondly, When I am trying to create a beneficiary using one of the account number mentioned on the testing page - https://developer.flutterwave.com/docs/integration-guides/testing-helpers, I am getting the error - "Account resolve failed".

How to get around this error and is there a way to test it?