Print to PDF is a function within Google Chrome that permits webpages to be saved as .pdf files. It is not necessary to install any software on your computer or extensions in your browser, because the function is already existent in Google Chrome.
Open the Billing page (https://callision.com/billing), scroll down to the list of invoices, then open an invoice by clicking the "View" button.
After the web version of the invoice loads, press Ctrl+P to open the Print dialog and change the destination printer to “Save as PDF”. Hit the “Print” button and the invoice will download as a PDF document. You can also use Chrome’s print-to-PDF function to convert local HTML web pages to .PDF, as well as local image or text files by simply opening a file in Chrome and printing it to PDF.