Return type of Vonage\Client\Credentials\AbstractCredentials::offsetGet($offset) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/vendor/vonage/client-core/src/Client/Credentials/AbstractCredentials.php on line 31
Please, upgrade
vonage/client
to version 3.0.0For PHP 8.1: