It is normal for a toddler to eat their poop.
Just like it's also normal for a toddler to play with their poop but although it's normal for the toddler to eat their poop it needs to be stopped.
If the toddler is in diapers and digging the poop out of their diaper and eating it you need to watch the toddler more closely and change the toddlers poopy diaper before they have a chance to get to the poop.
Or put duct tape on the diaper all the way around it and put the toddler in footie pajamas such as the Little Keeper Sleeper so they have no access to their diaper and poop.
The toddler eating their own poop is unlikely to harm them but it's best to stop the habit as soon as possible because it is gross.
Eventually the toddler will outgrow the phase of eating their poop and playing with their poop though so that is good news.