If a question is asking for external resources, whether it's software, games, servers, websites, whathaveyou, it's off-topic. The entire class of recommendation questions don't belong here.
That said, rarely these questions can actually be XY questions; try to see if there's an underlying problem that the question is trying to solve. That's what we try to do with Minecraft mod recommendation questions. If there's something there that asking for a resource is supposed to solve, we can always try to surface that part, remove the request for a resource, and leave it at that.
However, most often, we don't have the information needed to surface the problem, if there actually is one. For questions where no problem exists, and asks for an external resource, vote to close.
A good rule of thumb we can use, although it isn't perfect: If you're asking how to find something in-game, good to go. If you're asking for us to find something out-of-game, probably not.