Quiet Time

I like re-branding nap time around the age of 3 and calling it "Quiet Time". This way, when kids stop sleeping at some point (typically between 3.5 and 4.5 year sold), they are used to spending and hour or two in their room quietly during the day. Give them quiet toys to play with so they stay entertained but their body also has a chance to rest. And you have a break!

If your child struggles to stay in their room alone, I recommend practicing during a different part the day. Maybe play in their with them and then leave for a minute to use the bathroom and come back and give some praise "great job playing in your room by yourself"

During quiet time, you can use a timer to encourage staying in their room for short chunks of time - like 5 minutes - and then build up from there. You can use rewards if you'd like.