So basically why im doing this thread is because there are a lot of open questions to install twrp/root on the SM-A105FN/DS so after i sucessfully did i wanna share the way here:

1.The first step we all now: Settings>About Phone>Spam click BuildVersion till the toast says youre a developer<Back to Settings>Developer Settings>Enable OEM Unlocking.

2. Turn off your Phone.

3. Sucessfully turned it of? Nice! now hold up and down key and plug your phone in(Dont Press the Power button!)

4. Now your on the Pre-Screen from the download section, press and hold the volume up key(!!!WARNING THIS WILL ERASE ALL YOUR DATA!!!)

5. Get back into Download mode. this time only press Volume up shortly.

6. Open ODIN(FIle Attached), uncheck auto-reboot in options tab, and flash vbmeta_disabled.tar in AP slot.

7. Now reboot your phone but get instantly back into Download Mode.

8. Flash attached TWRP(Only this one seems to work)

9. Congrats you sucessfully installed TWRP on Your A10! but were not done yet!

10. Instantly boot into TWRP(Otherwise you will brick your FW)

11. In TWRP allow writing by swiping

12. Go to Install and move Disable_Dm-Verity_ForceEncrypt_10.28.2020.zip to your SD or Internal Storage.(From your PC) and install it with twrp(leave as it is and just swipe!)

13. Congrats everything should work now. the following steps are optional
13.5 CLEAR CACHE DALVIK CACHE AND DATA FOR THE FOLLOWING STEPS
14. Move the lineage os file to your SD or Internal storage(Download Here or from Attached FIles)

15. Install with TWRP(install gapps as needed (Can be Found by googling Android 12 Gapps!))

16. Clear Dalvik/Art Cache

17. Enjoy Lineage OS