To resolve this issue, please follow these steps:
1. Ensure that you have a strong and stable internet connection.
2. Check if your phone number is correct. The country code should be correct and there should not be any leading zeroes in front of your number.
3. Make sure you can receive SMS messages. Your carrier may be blocking them.
4. If you are trying to activate וואצאפ on a new phone, make sure that your old phone is switched off or put on airplane mode.
5. Wait for the countdown timer to finish and then tap on 'Call Me' to receive a phone call with the verification code.
6. If you still don't receive the code, you may need to contact וואצאפ support.