Does Plesk service (sw-cp-server) support the version 1.3 of the TLS protocol on Linux server?
The support of TLS v1.3 has been implemented in Plesk Obsidian and is available only for RHEL 8, Ubuntu 18.04, Ubuntu 20.04, and Debian 10 because this protocol requires version 1.1.1 of OpenSSL, available on official repositories of the aforementioned OSes. Also, TLS v1.3 support is enabled by default on all new Plesk installations on these OSes.
To enable TLSv1.3 for
sw-cp-server service follow the instructions from the article: How to enable or disable TLS protocol versions in Plesk for Linux?
Note: Plesk Onyx does not support TLS version 1.3, and its support is not planned to be implemented under it.