1. Open ROM Tool N9 -> Apply Essential Fix -> Restart
2. Open ROM Tool N9 -> Mods & Fix -> SafetyNet Fix and Apply Fix.
3. Open ROM Tool N9 select "update and bug fix". Navigate to Note 9 and then download all the files in the folder "Edxposed for Q" and place it in the phone memory.
4. Install EDxposed Manager apk.
5. Open Magisk, Modules and add the first file "Riru Core" from the folder which you downloaded and place it in phone memory. Once installed Click on Restart.
6. Open Magisk, Modules and add the second file "Edxposed yahfa v0.4.6.3, once installed restart again.
7.Open Edxposed Manager and it should show "Framework Active". Now select Modules and Enable Edxposed Manager.
8. In Edxposed Manager, go to settings and scroll down till Framework and under that Enable "App List Mode" and "Pass SafetyNet". Restart Phone once.
9. Go to Magisk and under settings enable Magisk hide and then select "Hide Magisk Manager" change it to some name. now it will reinstall Magisk. Once done wait for a while and check safety net. It should work. Else restart and check.