As you can see, this flag was introduced 3 months ago feat(mutations): Introducte mutatoinsNquadLimit by ashish-goswami · Pull Request #6561 · dgraph-io/dgraph · GitHub - so it wasn’t backported to 20.07.x - It feels like it is part of 20.11.x only. @hardik/@dmai can confirm.
If you are using the latest docs or master, you can bump into some unsupported docs for your version.
If you have found it in some 20.07.3 tag, it was in some rc1. And it should not be there. Cuz this PR 6561 is from October and 20.07.X is from July. Also, I don’t see any backport PR, have to do a deeper look if so. Or wait for Hardik to confirm.
Also, Daniel and Hardik can tell if we could do a backport to 20.07.3.