Firstly, if relevant, has payment been made for the order? This plugin will instantly print orders made via manual payment methods, even before payment (e.g. cheque, cash, BACS); for other payment methods where payment notification is automated (e.g. PayPal, Stripe, Authorize.Net, etc.), the order is printed when payment is made. If using PayPal, then please check your PayPal account to see that the payment has actually completed – more than one customer has tested using a freshly-created PayPal account that isn’t capable of processing payments yet, because PayPal haven’t lifted the initial restrictions on the account. Note that “when payment is made” does not mean the same as “when the order status changes” (technically, it is when WooCommerce fires the internal action woocommerce_payment_complete). Often when people are testing they do not realise this and expect something to print if they manually manipulate order status. (If you do want to always print when order status changes, go here for help).
Have you selected any templates to actually be printed? Check the plugin settings in WooCommerce -> Settings -> General.
Is your printer yet connected to Google Cloud Print? This plugin sends a print job to Google Cloud Print… until your printer is actually connected to Google Cloud Print, it won’t print anything. Use the “Print” button on this page – https://www.google.com/cloudprint/ – to send test print jobs to your printer via Google Cloud Print.
If your printer is connected to Google Cloud Print, then is your website correctly set up to connect to Google Cloud Print? Go to the Settings -> Google Cloud Print page in your WordPress dashboard and print out a test. If that does not work, then your website is not yet connected to Google Cloud Print.
Is your printer switched on? If it needs to be connected to a computer, then is it – and is the computer switched on? You can check at this link to see if Google Cloud Print has received your job: https://www.google.com/cloudprint/#jobs. If the job is in your Google Cloud Print queue, then this plugin has finished its work – the problem lies further down the line, and you need to look at where.
You can also switch to using “Google Drive” (PDF) as your printer (in the Settings -> Google Cloud Print page) to help work out if the problem is on the road between your WordPress site and Google Cloud Print, or if it’s in between Google Cloud Print and your printer. After you have successfully saved a PDF to Google Drive, you can then try uploading that PDF manually into Google Cloud Print at https://www.google.com/cloudprint/#jobs – does that work? If not, then the problem lies somewhere in between Google Cloud Print and your printer, and isn’t related to this plugin.
You should also make use of the option to send an email with debugging information (in WooCommerce -> Settings -> General), as in this screenshot (send this log to us if requesting support, together with information from all the above items, e.g. your PDF from Google Drive, payment method, etc.):