The update would come from Alcatel or your carrier, but it looks like they didn't provide updates after 4.2.

If there was a custom Android 5.0 ROM made by users for your phone you could root and install that, but I'm guessing there isn't since there's little activity with the phone.

More info:

The two main advantages of rooting a phone are being able to put a custom ROM on the phone and the ability to install apps that require root.

Two downsides - there is a small chance you can brick the phone, and if it's newer you may void the warranty.

The root process is different for every phone, so follow instructions for your specific device. Here is more information about rooting:
https://androidforums.com/threads/rooting-best-practices.450904/
https://androidforums.com/threads/root-terminology.443075/
https://androidforums.com/threads/youve-went-and-rooted-the-phone-now-what.617220/