If you are running Catalina you will have to disable the SIP:
Turning Off Rootless System Integrity Protection in OS X El Capitan 10.11.x or Later
Again, the vast majority of Mac users should not disable rootless. Disabling rootless is aimed exclusively at advanced Mac users. Do so at your own risk, this is not specifically recommended.
Reboot the Mac and hold down Command + R keys after the startup chime, this will boot OS X into Recovery HD. When the Utility Menu appears, select the Terminal from the Utilities menu in the menubar. Paste the following command into the terminal then hit return: csrutil disable; reboot.
You’ll see a message saying that System Integrity Protection has been disabled, and the Mac needs to restart for changes to take effect. The Mac will then reboot itself automatically.
Once the Mac boots up again, System Integrity Protection will be disabled entirely in OS X.
How to Re-Enable Rootless System Integrity Protection in OS X
Simply reboot the Mac again from the Recovery HD as directed above, but at the command line use the following syntax instead: csrutil enable; reboot