9 year-old, half-day fast?

In teaching kids to fast before bar mitsva little by little, what is the rabbi’s guidance? Should we attempt having our 9 year old fast the first half of Kippur? Would this apply to any other fast (major or minor)?

Thank you.

The Rabbi doesn’t encourage children to fast. No need to begin fasting until bar/bat mitzvah

How does that shtim with שולחן ערוךs psak? Thanks! ksiva veschasima tovah!

It Shtims with Rav Abadis Psak!