Thanks to @ScrewTSW he found at http://www.htcmania.com a working TWRP Recovery from totmakina
found : http://www.htcmania.com/showthread.php?p=27398885
to reboot into recovery most elephones works with hold vol+ and power at the same time.
this method dont work for the S8 and i did not found a working method yet.
but its not a problem if you follow this:
for people with stock rom /unrooted
1. download all files and place them on your desktop
2. flash my modified boot.img (magisk root) with flashtools
3. flash TWRP recovery with flashtools
4. reboot the Phone and install magisk manager app (link https://www.apkmirror.com/apk/topjohnwu/magisk-manager/)
5. start magisk manager , it will tell you that your phone has root
6. go to playstore and download the app called reboot recovery ( its a very small app)
7. reboot to recovery.
9. Now you have twrp and you are able to flash zips or custom roms
TWRP S8 : https://androidfilehost.com/?fid=889964283620766601
Patched Boot.img : https://androidfilehost.com/?fid=673791459329061887