During the installation you can face an error like this:
Follow this instruction to solve the problem:
1) Restart your Mac
2) As your Mac restarts, press and hold down the Command(⌘) + R keys immediately upon hearing the startup chime. Hold the keys until the Apple logo appears to get the computer into Recovery mode.
3) From the top bar select Utilities > Terminal, and execute this command:
4) Restar the Mac and log into Administrator's profile
5) Open the Finder window and select from the top bar Go > Go to Folder and type
6) Create a folder named tmp and type in your password
7) Launch AdGuard installation
As the installation is completed, restart your Mac in Recovery mode using the instruction above and execute
csrutil enable command in Terminal to enable system protection.