This Flyme OS is an official, however, comes via customized ROM for Meizu E3. We share the direct download link below. To flash Flyme OS 6 on Meizu E3 have to install TWRP recovery or any custom recovery. even if you have a custom recovery then skip this step and direct continue with the step to install custom ROM. so let’s go guide to install Official Flyme OS 6 for Meizu E3.