Automating Facebook DMs: Seeking Insights on Marketplace Bots

Has anyone here successfully automated Facebook DMs? I’m working with a client who wants to set up a bot that replies automatically to messages coming through Facebook Marketplace, similar to how ManyChat handles Instagram DMs. Before I start testing, I’d love to hear if anyone has already figured out a working setup to handle Facebook DMs (especially Marketplace messages). Any insights or examples would be super helpful!