It seems like they're disengaged yeah, or maybe you should find a way to incentivise them somehow. If you don't mind me asking - what's the app url?
Regarding the marketing person - I guess you can try both. I myself haven't had good luck with marketing people, although in recent times I've found one lady which is great at what she does. Unfortunately way too expensive for me at the stage my apps are. And I've also struggled a lot to find a qualified marketer willing to partner on a product.
One thing I can say - if you've grown organic traffic via SEO, it'll probably be hard to engage with existing customers since you don't know much about them.
What has worked from my experience: if you've defined a proper ICP figure out where they hang out - forums, subreddits, etc. Try to look for places where they could potentially be talking about the problem (if you can't find such a post then maybe make one yourself to kick it off). And figure out a way to engage in a conversation with them, provide value without selling the product and just ask for 5 minutes of their time. It's a very slow process until you figure it out, but once you do the data is valuable and allows you to build the product based on it.