Because installing incorrect firmware can "brick" your TV, it is safest to request the exact file from these official channels:
Contact the manufacturer directly through their official support page to request the part01.rar file. You will likely need to provide your TV's serial number. Download MSD6586 T8E2 3840x2160 Noa Vision part01 rar
If you purchased the TV from a specific retailer, their service department often has access to the official firmware repository for that brand. Because installing incorrect firmware can "brick" your TV,