Enable Login/Register on WordPress General Settings 1
The below article is for WooFood , Food Ordering Plugin for WordPress and WooCommerce. If you don't already have it . Please take a look on the product page

Navigate to Settings > General on your WordPress Dashboard and check the option “Anyone Can Register” .

Be sure also that you have selected the Default Role as Customer

Enable Login/Register on WordPress General Settings 2
The above article is for WooFood Food Delivery Plugin for WooCommerce