I cannot help but recommend the application LULU, which has been the most valuable asset in my personal quest to protect my privacy. This app will serve the purpose...and more. I neither work for nor am paid to represent this company in any way. I have come to deeply appreciate it though, and I would like to see it continue so that I can continue to use it.
The company, Objective-See, makes free, open source security software while specializing in MacOS. I have followed some of their research publications / conference presentations and find that this small company appears to position itself on the 'cutting edge' of privacy protection. A listed 'friend' is Malwarebytes, so I am not sure how 'small' this company is. Of course, time ages wine beautifully. In other domains, time does nothing so beautiful. Be responsible for your own due dilligence. In my estimation, it's trustworthy and most useful at this point in time.
See attached images. The relevant point here is that the app becomes a network filter to block incoming and outgoing network requests / communications, at the global level, for which you can create a custom block list. The blocklist is a simple text file to which LULU is directed. My blocklist contains a few specific addresses that effectively block Google login windows from appearing. The app can be easily toggled on and off in the case I want to log into Google. If Google changes the addresses, I can find the new address by inspecting the source of the page and updating the address in the blocklist. Ready-made blocklists can also be gathered online for free from leading security / privacy / malware centric platforms. Advanced users can automatically update their blocklists by tapping into APIs. All Apple programs / applications can be allowed free-range communications by checking a box. For third-party software, the same option exists. But I do not allow third-party software this option. Instead, LULU blocks them and shows me the destination address of the intended communication. I am given the option at this time to permanently block, temporarly block, or allow.
I have been using the app for about two years now, and it has worked beautifully on my Intel Mini, late 2014.