Hi, welcome to the forum. Glad you joined.
Did you count the days correctly? That is a common mistake. An egg does not have a day's worth of development when it first goes into the incubator. You say "one" 24 hours later. An easy way to check your counting is the day of the week you put them in the incubator or under a hen is the day of the week the 21 days are up. If you started them on a Thursday, the 21 days are up on a Thursday.
All eggs do not hatch at exactly 21 days. Due to many different things they can hatch as much as 2 full days early or late. Things like heredity, humidity, how and how long they were stored before incubation started, and just differences in individual eggs can make a difference. One common cause is the average incubation temperature. If it is high they can be early, low and they can be late. It took me three times before I got my average incubation temperature right. The presets on the incubators are not always correct.
In my opinion. the more you fool with the eggs during hatch the more opportunity you have to cause harm. I know of nothing you can do at this stage to help them hatch. A lot of people on this forum handle eggs at this stage but my suggestion is to sit on your hands until the end of 23 days before you do anything unless you see something going on inside the incubator that demands your immediate action.
Good luck!