when should I start to wear an brief for my 2 year 1month old boy. he still wearing diaper

A. From the age of 6 to 7 months itself you should make your child wear briefs or underwear whatever it is because diaper should not be used on 24 x 7 and you cannot use nappies after 6 to 7 months it’s useless so you should have made your child wear an underwear from the age of 7 to 8 months itself