Hi. I have a Kindle fire 7 hdx 3 gen. Mod KFTHWI SYS 4.4.3 and a Macbook air running Catalina 10.15.4 (19E287). I want to install pure andriod on the tablet. So far I have figured out how to root it. It is rooted. I have downloaded SDK platform tools and got tablet into fastboot. Now I'm stuck. Don't really know how to proceed from here. I know I need to unlock the bootloader in order to keep going. Any help would be appreciated.