TWRP 3.2.1-0 is an update on the previous version of TWRP 3.1.1-0 bringing better compatibility for Android Oreo. The full changelog is as below
Minui fixes (cryptomilk)
Better android-8.0 compatibility in ROM trees (Dees_Troy)
Fix missing library in android-8.0 (nkk71)
Fix inconsistent SDCard naming (DevUt)
Default to TWRP restore instead of adb backup restore to fix restore on fresh TWRP boot (jlask)
I have ported this new version of the recovery to the Infinix HOT 4 Pro alias X556 running on Nougat XOS skin with 3.18.35+ kernel. You can use this recovery to root your X556, make nandroid backup on top of flashing custom Roms from your favourite developer
DOWNLOAD
Password: ahq254
INSTALLATION GUIDE - ROOTING
1. Download the file from the link above and extract
2. Launch Sp Flash Tool and load the scatter in the extracted folder
3. Click download button on flash tool and connect your Hot 4 Pro while switched off
4. Boot into recovery when flashing is done - Use Power Key + Volume Up
5. In recovery flash supersu or magisk to obtain root on your device
6. Reboot after you are done
7. Enjoy