Sandbox requests fails unexpectedly even with valid credentials

[mainangethe]

Summary:

Even with correct sandbox username and API key, the gem fails to send SMS through sandbox endpoint. No meaningful error message is returned unless manually debugging the connection.

Precondition:

• Valid sandbox credentials
• Internet access

Steps to Reproduce:

require 'AfricasTalking'

at = AfricasTalking::Initialize.new('sandbox', 'valid_sandbox_api_key')
sms = at.sms

response = sms.send(
  message: 'Test Message',
  to: '+2547XXXXXXX'
)

puts response

Expected Result:

Response with SMSMessageData including status and recipient

Actual Result:

Error: AfricasTalking::AfricasTalkingException: The supplied authentication is invalid

Notes:

Docs suggest sandbox is fully supported, but actual use via gem fails
No fallback or warning that sandbox environment may not be available
Users waste time debugging gem, credentials or logic