Duplicate contacts are created when numbers added lack an area code following the country code. This occurs despite initial contact through a WhatsApp template.

For contacts from Mexico, if the number added after the country code "+52" does not include the area code digit "1", the system creates a duplicate contact, even after a WhatsApp template is sent.

Implement a feature to automatically verify and append the necessary area code after the country code when a new contact is added.

Example:

For contacts in Mexico, the system should automatically check for the presence of the digit "1" after the country code "+52". If absent, it should automatically insert the digit "1". This adjustment aligns with WhatsApp's requirements for Mexican numbers.

Manually append the appropriate area code to each number during import. The final format should consistently follow the pattern: +(country code)(area code) without the "1" after +52.