I could not find anything about Public Key Pins (HPKP).
Here’s an article on it and security companies advice:
Configure the webserver or website to always force this header. This can be done using the
following configuration directives:
Apache webserver:
Header always set Strict-Transport-Security “maxage=31536000; includeSubDomains” NginX webserver:
add_header Strict-Transport-Security “maxage=31536000; includeSubdomains” always;
Microsoft IIS
webserver: In the IIS manager choose “Add Custom HTTP Response Header” → Name: “Strict-Transport-Security” → Value: “max-age=31536000; includeSubdomains”