Here is dosing instructions.
Says you can take missed dose as follows:
Do I have to take Tresiba® at the same time every day?
Adults can take once-daily Tresiba® at any time of day, if needed, so they can decide on a time and place that work best. Children must take their dose at the same time every day.
Adults who miss or delay a dose should take Tresiba® as soon as they remember, then continue with their regular dosing schedule, making sure there are at least 8 hours between doses. If children miss a dose, their health care provider should be contacted and blood glucose levels monitored more frequently until the next scheduled dose.