Keeping a 1yr old sleep at night

I’m needing advice on how to keep our one year old sleep during the night she use to stay sleep until 2months ago and now it like she wakes up every 2-3hr and we have to go and pat her back to get her back down and sometimes she doesn’t want to go back down. She doesn’t take that many naps during the day about 2. She eats before bed, and has a clean diaper. Anyone have any advice that can help?