In most cases, not a scam...
Perhaps you are located within the UK - which has recently enacted stronger age-verification legislation under the UK Government Online Safety Bill. Some additional information can be found here:
Legal - UK Online Safety - Apple
When updating to iOS/iPadOS 26.4, it is necessary to complete a robust age-verification process - the required steps being determined by how much information Apple already possesses about you and your Apple Account. In some circumstances, Apple will verify your age using a Credit Card registered in your name - and for this reason, you may be required to provide this information.
If not using a Credit Card, other forms of ID are accepted. Suitable ID is documented here:
Age requirements for managing an Apple Account in the UK – Apple Support (UK)
Additional information about age-verification can be found here:
If you're asked to confirm that you’re an adult – Apple Support (UK)