On a Mac, some packages (i.e. .app files) can be executed under Run As Admin by dragging them over the Admin By Request icon in the dock. However, Full Disk Access (FDA) must be enabled first.

To enable FDA, refer to Enable Full Disk Access (FDA).

For any .app file, initiate Run As Admin by dragging and dropping the application file over the Admin By Request Dock icon. At the account control pop-up, enter credentials and hit OK to run the installer as an administrator. Note that this works only for .app files; it does not work for .pkg files.