Why I cannot find options to enable Linux subsystem?

If you cannot find the “Developer Options” entry in the Settings to activate the Linux subsystem, it is possible that CPU virtualisation related features are disabled. Different motherboards have different BIOS setup screens and the relevant settings can be found in the following figure.

If you do not find the relevant settings in the BIOS, it is possible that your device CPU does not have virtualisation-related functions and cannot support Linux subsystems.