delete issue

In previous iOS versions, there has been a facility to prevent apps being deleted without entering the passcode. I used this, and the ability to prevent in-app purchases, to prevent my inquisitive Grandchildren from doing things that they oughtn't! Now that I am on iOS.13.n, last night I...

Wife subscribes to digital Vanity Fair magazine. Each issue is kept locally and is huge. How can I delete each single issue after reading? Thanks.