ISO/IEC 18013-5 (Personal identification — ISO-compliant driving licence — Part 5: Mobile driving licence (mDL) application) is a potential solution for this. https://www.iso.org/obp/ui/en/#iso:std:iso-iec:18013:-5:ed-1...

It would allow someone with an mDL on their device to present only their age instead of other identifying information.