Function queryUsernameExists

queryUsernameExists(
    username: string,
    key?: string,
): Promise<
    QueryUsernameExistsResult
    | QueryUsernameExistsKeyRequired
    | null,
>
Check if a WhatsApp username (@username) exists

Some accounts protect their username with a PIN. When the account has PIN protection enabled, this function returns { keyRequired: true } instead of contact info. Pass the numeric PIN as key to unlock the result.
Parameters
- username: string
- Optionalkey: string
Returns Promise<QueryUsernameExistsResult | QueryUsernameExistsKeyRequired | null>
Example
```
// Basic lookup
const result = await WPP.contact.queryUsernameExists('someusername');
if (result && 'keyRequired' in result) {
  // Username is PIN-protected — prompt the user for the PIN
} else if (result) {
  console.log(result.wid); // The contact's WID
}

// With PIN
const result = await WPP.contact.queryUsernameExists('someusername', '1234');
```
- Defined in src/contact/functions/queryUsernameExists.ts:66