You can use the timer and smart alarm in the full version of Endel for Alexa:
To start the timer, select a soundscape and say how long you want it to run for. For example, "Alexa, start Endel and play Focus for 15 minutes."
To set the alarm, select a soundscape and end time. For example, "Alexa, start Endel and play Sleep till 8 a.m."
Don't worry if Alexa doesn't accept the name of the soundscape or the time. She will ask for the missing information.