Hi Kha3,
To help us get a better understanding of the issue, we’d like to ask a few questions.
1. Has that option appeared in the past, or have you always experienced this?
2. If the option has appeared in the past, were any changes made to your device or its settings before this happened? If so, what was changed?
3. Since noticing this, has your device been restarted? If so, does restarting change the issue at all?
4. Under Settings > Screen Time > App & Website Activity, does it say "Turn On App & Website Activity"?
The above details will help us plan how to proceed.
Please also check out this link, which has information on check if Screen Time is enabled, and managing Screen Time settings, which may be helpful: Get started with Screen Time on iPhone
Go to Settings
> Screen Time, tap App & Website Activity, then tap Turn On App & Website Activity.

Thanks!