There are no true Antivirus Products available for iOS/iPadOS. Those that claim to provide AV protection are little more than “snake oil”, have negligible (if any benefit) and for Apple devices should generally be avoided. Very often, Apps of this nature introduce more issues than added benefit.
Unlike traditional Operating Systems with which you may be familiar, iOS/iPadOS uses a sandboxed security architecture. As such, Apps cannot access any data outside of their own sandbox - and cannot access the storage and resources of other Apps. As such, it is impossible for an Anti-Virus App to scan the filesystem.
For iOS/iPadOS, the Norton 360 App employs a potentially dubious network proxy - that attempts to intercept and examine network traffic.
While Norton and similar Apps have limited benefit, there are useful security enhancements and mitigations that can add security to your device - such as adding a good content/ad-blocking product (e.g., 1Blocker) - and use a security-focused DNS provider (e.g., Quad9) and encrypted DNS transport protocols (DoH, oDoH, DoT).
