iOS does not have "Keychain Access" as a named setting or app. MacOS has both Keychain Access as a standalone app, and Passwords as a section in your settings.

iOS does not have "Keychain Access" as a named setting or app. MacOS has both Keychain Access as a standalone app, and Passwords as a section in your settings. The latter is dedicated to purely passwords that you, as the user, make. Keychain Access also contains passwords for Wi-Fi and other systems.