I just wanted to clarify something that has caused me a fair bit of head scratching in hopes it will save other people some time.
Zapier state that they support MongoDB - but this is not the case in any real sense. They only support versions up to 2.6 which was released in 2014 and where security support ended in 2016. I have suggested to their support team that they remove the connector from their list of supported apps as it simply isn’t true (unless you are running a dangerously out of version of MongoDB from over 8 years ago).