It's up to you how you strongly you feel about the bedtime. Just some ideas...
You could give her the option of reading quietly until she's sleepy (or some other agreed-upon activity) - she might feel that she has some control over it, which is what I find my 3 yo really wants most of the time.
Otherwise, maybe try to just keep calmly but firmly putting her back to bed, no fuss, no smack, no arguments. Just keep it boring and unemotional. If she's doing it for attention or a reaction, don't give her one. You'll probably have to do it a thousand times but it might do the trick! Also, make sure she's getting enough time/attention from you during the day.
Or you could use some kind of reward system - this usually works well with my 3 yo. You can discuss it with her during the day, that it would be really great if she could stay in bed and make a chart so that after a certain number of nights where she stays in bed she can get a special treat.
These are only some suggestions, as it really depends on what might work with your DD's personality. Good luck