How to enable OCSP Stapling and HSTS for Plesk interface?
This functionality is yet to be implemented in Plesk. Vote for the corresponding feature suggestion at UserVoice portal.
Top-ranked suggestions are considered to be included in future Plesk versions.
The following workaround can be applied:
Connect to the server using SSH.
Open the file
/etc/sw-cp-server/conf.d/ssl.confin text editor and add the following content to it:
add_header Strict-Transport-Security "max-age=31536000" always;
resolver 126.96.36.199 188.8.131.52 valid=300s;
Restart sw-cp-server to apply changes:
# service sw-cp-server restart