How to child lock an iPhone or iPad for a kid or baby

Apple's Guided Access feature allows you to lock your iPhone or iPad into a single app, such as Netflix when watching a video, and control which features are available for each specific app.

Source : https://www.pocket-lint.com/guided-access-kid-mode-on-iphone-and-ipad-what-is-it-and-how-do-you-use-it/