You'll need to install or enable the socket extension. The error "Call to undefined function socket_create()" occurs when the socket extension is not enabled or installed on your server. The socket_create() function is a part of the socket extension in PHP, and it allows you to create a new socket endpoint for communication.

Check All Config

<?PHP 
phpinfo();
?>

if you need to install the socket package

sudo apt-get install php-sockets

After that Go to php.ini and just uncomment 

Manual process

;extension=php_soap.dll

extension=php_sockets.dll

;extension=php_sqlite3.dll

;extension=php_tidy.dll

;extension=php_xmlrpc.dll

;extension=php_xsl.dll

Use Terminal Command Line

cd /etc/php/7.0/cli

sudo nano php.ini