Please advise whether I can pair model PA4010 with WPA4220. Thanks
All of our powerline devices are compatible with each other, so different models can be used with each other. But all of them should be working in same circuit. So, yes, there is no problem to pair model PA4010 with WPA4220.
About how to pair them to work, please refer to: https://www.tp-link.com/faq-1615.html