Choose a content type with the tabs for the qr code you want to create (URL, Text, Email…). After choosing your type, you will see all available options which you can change or enter. Enter your data (URL, Text, Email…). Additionally you can set a color or an effect for your qrcode. You can also set a logo-image to display on your code. You can use a predefined gallery-image or upload an own logo. Enable the logo-option with the checkbox. Set a resolution-size for your qrcode. Use the ‘Create QR-Code’-button to see your generated qrcode in the preview window. Use a high resolution setting if you want to get a png code with print quality. Now you can print the code for diffent purposes or download the image files for your qr-code as .png or .svg, .pdf, .eps vector graphic. The logo-setting currently only works for .png files. Vector formats will contain no logo or effect. Source.