Using Instagram to promote your website
In a similar way to Facebook, Instagram can be used to promote your website. The fundamental interface is more visual based and the estabished users of Instagram will be more familiar with the look and feel. In addition there will be Internet users that may not want to use Facebook, even though Instagram is owned by Facebook and the security concerns will be the same.
Like Facebook users will be able to make comments on your posts and on your website.
One has to remember that Instagram is owned by Meta
I have been told that Instagram is a "far more friendly place".
The problem as I see it is that you may not want to have an Instagram account. I feel that there is a large measure of FOMO (Fear of Missing Out). While I am curious to see what those that think Instagram is a good way of promoting themselves of their enterprises are actually posting on it.
At the moment I can't really think what else would lead me to re-create an Instagram account. True, there is things that I see promoted on websites and Facebook that attempt to steer me to Instagram but I am just not that interested. The only reason that I have a Facebook account, in a false name, is to do just that - see what others are posting.
Advertising
One of the main reasons that I have my reservations is that if you search for how to use Instagram to promote your enterprise the results are from companies that want to sell you a service to do so. An example of this is Shopify, while this could well be what you want to do (sell a product or service online) I am not sure if the promotion of an event works the same way.