Fix: Correct backup codes usage statement for all affected versions (product-is#25714)

Updated the misleading statement about backup codes in SMS OTP documentation.
Backup codes should be used as a fallback when SMS OTP is enabled but
temporarily inaccessible, not when SMS OTP is disabled.

Affected versions: 6.0.0, 6.1.0

Author: wso2-engineering-bot

en/identity-server/6.0.0/docs/guides/mfa/2fa-sms-otp.md

@@ -222,7 +222,7 @@ To allow users to disable SMS OTP:
 
 ### Configure backup codes
 
-Optionally, you can configure backup codes to be used when SMS OTP is disabled.
+Optionally, you can configure backup codes to be used as a fallback when SMS OTP is enabled but temporarily inaccessible (for example, when a user cannot receive the SMS).
 
 To configure backup SMS OTP codes:
 

en/identity-server/6.1.0/docs/guides/mfa/2fa-sms-otp.md

@@ -222,7 +222,7 @@ To allow users to disable SMS OTP:
 
 ### Configure backup codes
 
-Optionally, you can configure backup codes to be used when SMS OTP is disabled.
+Optionally, you can configure backup codes to be used as a fallback when SMS OTP is enabled but temporarily inaccessible (for example, when a user cannot receive the SMS).
 
 To configure backup SMS OTP codes: