Notice: Undefined index: num_cliente in /var/www/html/us_plan/sms_sender_digital.php on line 5

Fatal error: Uncaught Twilio\Exceptions\RestException: [HTTP 400] Unable to create record: Invalid 'To' Phone Number: X in /var/www/html/us_plan/twilio-php-main/src/Twilio/Version.php:88 Stack trace: #0 /var/www/html/us_plan/twilio-php-main/src/Twilio/Version.php(223): Twilio\Version->exception(Object(Twilio\Http\Response), 'Unable to creat...') #1 /var/www/html/us_plan/twilio-php-main/src/Twilio/Rest/Api/V2010/Account/MessageList.php(115): Twilio\Version->create('POST', '/Accounts/AC1a0...', Array, Array) #2 /var/www/html/us_plan/sms_sender_digital.php(21): Twilio\Rest\Api\V2010\Account\MessageList->create('+', Object(Twilio\Values)) #3 {main} thrown in /var/www/html/us_plan/twilio-php-main/src/Twilio/Version.php on line 88