It is important to keep track of the toddler’s wake windows and sleepy or tiredness cues to understand when it’s time for a nap. Usually, by 12 months of age, toddlers have a set or a fixed nap time.
Around 12-18 months of age, toddlers can have around 4-5 hours of awake time before bedtime or nap time. It is also beneficial to keep a naptime routine along with a bedtime routine which can signal the toddler that nap or bedtime is approaching.
Along with this, you can maintain a quiet environment to the extent possible, keep the room as dim and cozy as possible and play white noise (not exceeding 50 decibels) to improve the sleep space.