Thanks for your inquiry, here.
Your well-loved Samsung Galaxy A42 5G released in November 2020 with Android 10.
Samsung select devices launched in 2019 or later will be supported with firmware security updates for a minimum of four (4) years following their global launch, while select newer devices will receive up to five (5) years of security updates.
Monthly, quarterly and biannual firmware security updates will include patches for Android OS- related security issues released by Google, as well as, patches for Samsung-specific security issues.
Thanks for patiently waiting.