Doesn’t seem to be. It doesn’t make sense that he would be all alone if it was before IW. Why wouldn’t the rest of the avengers be able to help him? Possible though but would be silly to release this after Endgame. At least AM&TW had the IW tie in at the end.
The movie takes place after Endgame. It's been confirmed for a while that the narrative begins 'minutes' after Avengers 4. My guess is that Endgame undoes Infinity War and this movie begins with Parker on that same bus.
That's the difference between marvel and dc movies. marvel movies are more lighter and funnier, family type films (except for the end of you know what when you know what happened, spoiler) and DC tends to be darker. You can totally tell the parts of Justice League that Snyder directed, being a DC guy, and the stuff Whedon did, being more of a Marvel director.