use SimonSchaufi\TYPO3Phone\Validation\Validator\PhoneValidator;
use TYPO3\CMS\Core\Utility\GeneralUtility;

public function initializeUpdateAction(): void
{
	if ($this->request->hasArgument('address') && $this->request->getArgument('address')) {
		/** @var \TYPO3\CMS\Extbase\Validation\ValidatorResolver */
		$addressValidator = $this->validatorResolver->getBaseValidatorConjunction(Address::class);

		$validators = $addressValidator->getValidators();
		$validators->rewind();
		$validator = $validators->current();

		$phoneValidator = GeneralUtility::makeInstance(PhoneValidator::class, [
			// If the user enters a number prefixed with "+" then the country can be guessed.
			// If not, the following countries listed in the array will be checked against
			'countries' => ['AUTO', 'DE'],
		]);
		$validator->addPropertyValidator('phone', $phoneValidator);
		$validator->addPropertyValidator('fax', $phoneValidator);
	}
}

use SimonSchaufi\TYPO3Phone\Validation\Validator\PhoneValidator;
use TYPO3\CMS\Core\Utility\GeneralUtility;

$phoneValidator = GeneralUtility::makeInstance(PhoneValidator::class, [
	// If the user enters a number prefixed with "+" then the country can be guessed.
	// If not, the following countries listed in the array will be checked against
	'countries' => ['AUTO', 'DE'],
	'types' => ['MOBILE']
]);

$result = $phoneValidator->validate('+3212345678');

if ($result->hasErrors()) {
	// Error handling
}

use SimonSchaufi\TYPO3Phone\Exceptions\NumberParseException;
use SimonSchaufi\TYPO3Phone\PhoneNumber;

if (!empty($address->getPhone())) {
	try {
		$phoneNumber = PhoneNumber::make($address->getPhone(), [$address->getCountry()->getIsoCodeA2()])->formatInternational();
		$address->setPhone($phoneNumber);
	} catch (NumberParseException $exception) {
		// Error handling
	}
}

use SimonSchaufi\TYPO3Phone\PhoneNumber;

(string) PhoneNumber::make('+3212/34.56.78');              // +3212345678
(string) PhoneNumber::make('012 34 56 78', 'BE');          // +3212345678
(string) PhoneNumber::make('012345678')->ofCountry('BE');  // +3212345678

use SimonSchaufi\TYPO3Phone\PhoneNumber;

PhoneNumber::make('012 34 56 78', 'BE')->format($format);       // See libphonenumber\PhoneNumberFormat
PhoneNumber::make('012 34 56 78', 'BE')->formatE164();          // +3212345678
PhoneNumber::make('012 34 56 78', 'BE')->formatInternational(); // +32 12 34 56 78
PhoneNumber::make('012 34 56 78', 'BE')->formatRFC3966();       // +32-12-34-56-78
PhoneNumber::make('012/34.56.78', 'BE')->formatNational();      // 012 34 56 78

// Formats so the number can be called straight from the provided country.
PhoneNumber::make('012 34 56 78', 'BE')->formatForCountry('BE'); // 012 34 56 78
PhoneNumber::make('012 34 56 78', 'BE')->formatForCountry('NL'); // 00 32 12 34 56 78
PhoneNumber::make('012 34 56 78', 'BE')->formatForCountry('US'); // 011 32 12 34 56 78

// Formats so the number can be clicked on and called straight from the provided country using a cellphone.
PhoneNumber::make('012 34 56 78', 'BE')->formatForMobileDialingInCountry('BE'); // 012345678
PhoneNumber::make('012 34 56 78', 'BE')->formatForMobileDialingInCountry('NL'); // +3212345678
PhoneNumber::make('012 34 56 78', 'BE')->formatForMobileDialingInCountry('US'); // +3212345678

use SimonSchaufi\TYPO3Phone\PhoneNumber;

PhoneNumber::make('012 34 56 78', 'BE')->getType();              // 'fixed_line'
PhoneNumber::make('012 34 56 78', 'BE')->isOfType('fixed_line'); // true
PhoneNumber::make('012 34 56 78', 'BE')->getCountry();           // 'BE'
PhoneNumber::make('012 34 56 78', 'BE')->isOfCountry('BE');      // true
PhoneNumber::make('+32 12 34 56 78')->isOfCountry('BE');         // true