Here You find Two Different Methods to sign in with your Instagram accounts.
The first Method (Username & Password): This “Non-official integration”, which you can schedule and publish your posts as “Feed posts, Story posts, IG Tv posts, and Carousel posts”, Whether it’s photos or videos.
Second Method (Login Via Facebook): It’s the official integration with Instagram to sign in to your account, but that can be worked only with account that linked to Facebook page, and for schedule and publish posts its will be working only with “Feed posts” Whether it’s photos or videos.
Note that: this method will non-support for “Story posts, IG Tv posts, and Carousel posts”.