Instagram's own app makes you log out and back in. The API does not — one authorisation per account, and then the same post can go to all of them at once.
Free, about a minute in the Instagram app's settings, and non-negotiable: Instagram's API will not publish from a personal account, for any tool. Do this first or the connection will not complete.
Each account authorises separately through Instagram's own screen. Connected accounts sit side by side and are selected like any other channel.
One post, several Instagram accounts, published natively to each. Save the selection as a named group if it is a set you use often.
The most common blocker, and it is Instagram's rule rather than a missing feature. No scheduler can publish to a personal profile.
Posting the exact same caption and media to several accounts is visible to anyone following two of them, and it is the fastest way to make a network of accounts look automated.
Ten images per post, which is Instagram's own limit rather than ours.
As many as your plan's channel count allows — 2 on free, 8 on Creator, 25 on Business. Each Instagram account counts as one channel.
Instagram Business and Creator accounts are linked to a Page in Meta's model, and the connect flow will ask for it. This is Meta's architecture, not an extra step we added.
Connect your accounts, upload a video, and publish. Takes less than a minute. Free to start — see plans.