@Shubham_Ranjan I’m using masOS Catalina. I have same issue. Even though i changes my terminal shell to bash. I was unable to run - mongo --nodb. As soon as try to run, the modal pops ups and says -
“mongo” cannot be opened because the developer cannot be verified.
I have followed all the steps of installation but unable to move forward due to above error. Please bring updates for macOS Catalina.