If a child is not potty trained by Kindergarten then they will not be able to attend Kindergarten unless they have an issue such as autism or other disability or incontinence that requires them to wear diapers.
All kids unless they have a health issue must be potty trained before they will be accepted into Kindergarten as teachers don't change a Kindergarten kids diapers.
Your child or kid should be fully potty trained by the age of 4 at the latest although most kids are potty trained by age 2 to 3 years of age.
The age at which your child should be potty trained is at least by age 3 to 4 years old.
Some kids are ready to potty train by 18 months to 2 years of age and some kids don't master the potty until around age 3 or 4 years of age.
If the child is not potty trained by 4 then you'll need to force the issue as they will need to be potty trained by Kindergarten.
The average age for potty training kids is between 18 months to 2 years of age.
That is for most kids who are ready to potty train at those ages.
Some kids are ready to potty train and get out of diapers as early as age 18 months and are fully potty trained by 2 years old.
The child may still need to wear diapers at night for bed wetting but they should be able to go all day without a diaper.
Some kids may not potty train and be out of diapers until age 3 years old to as late as 4 years old.
A kid will eventually potty train when they are ready.
It's normal for a kid to need to wear diapers for bed wetting from age 3 to as late as age 8 years old and even older.
Some kids will continue to wet the bed for quite awhile and it's normal and some kids may wet the bed until age 17 or 18 years old and some people wet the bed all their lives and that is also normal.
Forcing potty training too early can be harmful to the child's health because they may try to hold in their poop or pee and that can lead to kidney and bowel issues.