Since Apple made notarisation a requirement for those developing for macOS, it has made it progressively harder to run code that hasn’t been notarised. Code that is quarantined can be run if Anywhere is enabled in Privacy & Security settings, but not by adding it as a Developer Tool. Before considering using any of these, you must be absolutely certain that the code to be run is not malicious, particularly if it originates from outside that Mac. I noted previously the conflict in results returned by spctl and the xprotect command with respect to the effects of allowing code from Anywhere to be run. This confirms my previous conclusions that allowing apps from Anywhere in Privacy & Security settings doesn’t disable Gatekeeper or on-demand XProtect, but merely enables you to run signed apps that haven’t been notarised.