No. Storrito does not use Instagram OAuth. Connecting an Instagram account to Storrito is a password login, not an OAuth authorization flow — see How Does Storrito Integrate With Instagram? for how that connection works.
Signing in to Storrito itself (not connecting Instagram) goes through WorkOS AuthKit, our login provider. When you sign in, your browser is redirected to authkit.storrito.com and back to your Storrito workspace. That redirect can show up in browser history or in an IT department's security tooling looking like "an OAuth authorization flow" — but it's authenticating you into Storrito, not authorizing anything on Instagram. If you're checking a timeline for a security review, a Storrito sign-in and an Instagram connection are two different, separately logged events.
Your Instagram password is encrypted before it's stored. Storrito uses it to open an Instagram session on your behalf in order to post on your account — this is separate from, and unrelated to, the WorkOS sign-in above.