Woocommerce REST API Oauth consumer key parameter is missing

I have a WooCommerce website and I am building an app for it (HTML, ANGULARJS). I need to get the products from the website to show them into the app and I am using the REST API.

To get the products from WooCommerce I am using the WooCommerce REST API PHP Client Library and I manage to get the products appear on screen via PHP.

I need to get the products via the URL but when I go to http://example.com/wc-api/v3/products I get the error

{"errors":[{"code":"woocommerce_api_authentication_error","message":"oauth_consumer_key parameter is missing"}]}

I prefer not to add an SSL to the site, I’d rather stay on HTTP and I understood that the Client Library helps me with authenticating over an HTTP request.

How can I retrieve the products from the URL or how can I retrieve a oauth_consumer_key?