Filling doesn’t set

It's not in the recipe, and not absolutely necessary, but I'd cool it down to at least room temperature in a bowl of cold water- it only takes a few minutes and will make it easier on both your crust and your refrigerator. Just be sure it's still pourable when you add it.

The filling will set when it's chilled as long as the gelatin was properly dissolved in the mixture (fully dissolve so no particles are seen or felt; don't boil). The temperature at time of pouring doesn't matter. I wouldn't pour it in hot since that may lead to crust sogginess, but when I read the recipe it looks like it will be lukewarm at the pour step.