Conjuring 3?

When will "The Conjuring 3" be on Netflix or Amazon Prime?

The film will not be released until June 3rd, 2021 and this date is not yet certain, because many films are currently being postponed again.
If it appears on that day, it will still take at least a year before the film appears on a streaming platform. Conjuring 3 is also a big blockbuster that will probably be offered for sale at first.
Of course, the production company could sell this film to Netflix or some other streaming service, but I wouldn't hope so.

So at the earliest in summer 2022, but probably not until later.