You need to send your phone back to OnePlus to receive the update
If you dont know, the OnePlus 5 and OnePlus 5T is incapable of streaming HD Content from Netflix or Amazon Prime Video which has left many users disappointed but not anymore as OnePlus is finally ready to update the OnePlus 5/5T with support for Widevine Level 1 which is the main cause for not streaming the HD content on these OnePlus devices.
But updating to Widevine Level 1 is not that easy as it looks to be there neither OTA update nor a ROM you can sideload.
“The update can only be done through an authenticated PC due to the “security processes involved with updating the devices.” This means that users will have to physically send in their devices to OnePlus in order to receive the update, since the only PCs that are authenticated to handle the update are presumably at OnePlus offices” said David, OnePlus Community Manager.
You have to send your phone back to OnePlus and you can expect it back in no more than 5 working days. If you live in North America, Europe, India, or China, you won’t have to pay anything as OnePlus will cover the cost of shipping.
Interested users need to contact the OnePlus customer support team here for more information in setting up the return.