That specific recovery version acted as a bridge—a final patch of solid ground between the era of removable batteries (KitKat/Lollipop) and the sealed, A/B partitioned future.
Installing TWRP 3021 2021 on your device is a relatively straightforward process, but it does require some technical expertise. Here's a step-by-step guide to help you get started: twrp 3021 2021