Fatal error: Uncaught Error: Call to a member function client() on null in /var/www/lib/vendor/shopify/shopify-api/src/Clients/Http.php:164 Stack trace: #0 /var/www/lib/vendor/shopify/shopify-api/src/Clients/Http.php(74): Shopify\Clients\Http->request('api//graphql.js...', 'POST', '{\n product(i...', Array, Array, NULL, 'application/gra...') #1 /var/www/lib/vendor/shopify/shopify-api/src/Clients/Graphql.php(69): Shopify\Clients\Http->post('api//graphql.js...', '{\n product(i...', Array, Array, NULL, 'application/gra...') #2 /var/www/lib/StorefrontAPI.php(22): Shopify\Clients\Graphql->query('{\n product(i...') #3 /var/www/html/test.php(4): require_once('/var/www/lib/St...') #4 {main} thrown in /var/www/lib/vendor/shopify/shopify-api/src/Clients/Http.php on line 164