Is there a word for
disgusting people that call themselves influencer on Instagram who ask to stay at a hotel or eat food at a restaurant for free in exchange of promoting their business on Instagram posts? These people are not really well-known, but they have the nerve to contact people they think will let them do so. Most businesses hate them and even ban them.

How do you call this kind of people? Is there a noun for this?

Question

Is there a word for
disgusting people that call themselves influencer on Instagram who ask to stay at a hotel or eat food at a restaurant for free in exchange of promoting their business on Instagram posts? These people are not really well-known, but they have the nerve to contact people they think will let them do so. Most businesses hate them and even ban them.

How do you call this kind of people? Is there a noun for this?

Answer

I don't know of a noun for this. These people are not really swindlers or scammers, because they do deliver the promised service in exchange for their food or lodging or etc. They are exploiters of the perceived power of social media and misrepresenters of their own influence there, but that's not one single noun.

Maybe we need to coin a word for them: "Insta-scammers?"

Answer

'Influencer' is a term used on social media for genuine people with followers. For instance, someone with a youtube channel and several thousand followers at least. So, politely, you could just describe these people as fake influencers.

If you want to describe them more harshly, the term coined by Evelyn is great. Also, a general term used in English a lot is 'scam artist' (someone making a fraudulent offer and pretending it's legitimate). I would probably call them that and everyone will understand you as the term is well known.