Unable to receive verification code for Telegram after purchase

You need to have an SMS/MMS plan enabled by your carrier for the SIM/eSIM that you use on your device. Apple Inc. does not provide SMS/MMS services.

1. SMS/MMS Plan Requirement: To receive verification codes via SMS, you need an active SMS/MMS plan from your carrier for the SIM or eSIM in your device. Without such a plan, SMS messages, including one-time passcodes (OTPs) or verification codes, cannot be delivered.
2. Apple's Role: Apple does not provide SMS/MMS services. iMessages sent through Apple’s servers are not the same as SMS/MMS and require an internet connection. This distinction is important because OTPs and verification codes are typically sent as SMS messages unless specified otherwise.
3. Verification Codes via Third-Party Apps: If the verification code is generated by a third-party app (e.g., Google Authenticator, Microsoft Authenticator, Telegram), the app itself must be functional, and you must have access to it. Any issues with app-generated codes should be addressed by the app's developer or support team.
4. Phone Number Accuracy: Ensure that your bank, app, or other third-party service has your correct phone number on file. A mismatch or outdated number will prevent you from receiving verification codes.
5. Troubleshooting Tips:
   1. Confirm your SMS plan with your carrier.
   2. Check your device’s signal strength; poor reception can hinder SMS delivery.
   3. Verify that your phone number is active and properly registered with the bank, app, or service.
   4. Ensure the SIM/eSIM you are using is correctly set as your primary number for sending and receiving messages.
   5. Check for any blocked numbers or spam filtering settings that might interfere with message delivery.

By following these steps, you can address most issues with receiving verification codes.

Telegram is not an Apple product. Contact the app developer here --> App Support or Telegram support