Hey moms of toddlers!! I need your help! Please!

Hey mamas!

I am trying to transition my 15 month old daughter down to 1 nap while making her bedtime earlier. It was between 10:30 pm and 11pm for a long time. Today was technically the 1st day that I did the 1 nap. She woke up at 9am, I put her down to nap at 1pm and she slept until 4pm. 3 hours. I put her down for bed between 8:30pm and 9. She did not want to go to sleep at all. She was wide awake. And wanting to play. I thought for sure she would be tired. She moved around and talked to herself for about 45 mins until

I gave up and just let her stay up. Well, she didn’t go to sleep until almost 11. So her total wake time was about 7 hours! Omg. What did I do wrong? Did she day nap too long. Did I put her to bed too early? Do I wait it out and see if it gets better in a week or 2? I’m trying to create a schedule where she goes to sleep no later than 9pm and stays asleep until 8 or 9am. That works for our household. Please help!! Thanks so much!