QR-code is a deposit address written in a different form. There are 3 simple ways to generate QR codes for payments:
1 
npm: qr-image JavaScript solution with detailed instructions, it generates codes in png, svg, eps и pdf. It operates at the local level and doesn't require calling Google API.
2 Google QR code generator: 
Charts | Google for Developers
3 QR API (QR code API: command “create-qr-code” (generate QR code, QR code generator) ).
There's a text field that captures its content. Every time you press the "generate" button, you create a new request URL on API, and this URL has two main components- data and size . The first one is for text coding, the second one defines the size.