Introducing a cleaner, lighter more advanced way to add QR codes to woocommerce generated tickets:
Smart QRCode WordPress Plugin.
Smart QRCode is only 24.1KB in size. Simply upload, activate then enable, the plugin will do all the work for you. This plugin auto generates a unique QR Code and stores it for when your ready to process tickets. Smart QRCode allows you to process/check-in tickets via desktop, tablet or mobile. Just scan the code and your web browser will automatically open that product URL allowing you to nake a decision.