[Did you know that you must advertise on Instagram via Facebook Ads?]
There is no other way to advertise on Instagram. Instagram is a Facebook property, all ads on Instagram are placed via Facebook Ads.
So to be clear, advertise on Instagram through your Facebook Ads account.
I’m sure that is what most people were telling you to do, maybe you just missed the connection?
Also, don’t limit yourself just to Instagram, those same videos can be effective on any of the popular video-sharing platforms, including YouTube, Facebook, and Twitter, which all have a ton of traffic (more than Instagram). then there is LinkedIn, Vimeo, and other smaller platforms that might be worth targeting.
I advise that you pick just one channel at first (i.e. Instagram via FB ads), learn to master it and then add a couple more channel and master those.