Yes dogs can safely eat popcorn.
There's nothing harmful or toxic about popcorn that makes it unsafe for dogs to eat.
Just make sure the dog does not neat too much popcorn at once to avoid possibly choking especially on the seeds.
My dog used to eat popcorn with me and he loved it.
He lived a long healthy life so the popcorn never hurt him.
Dogs can eat most human foods without any issues.
So if you want to feed your dog some popcorn as a snack then you can do so.
Just make sure the dog is eating other foods such as dog food to stay healthy.
But popcorn in moderation is okay for the dog.