You do not specify what country you are in (CE/FCC area), nor what platform you are using (iOS/Android), nor whether you are flying by phone or remote controller!
So a little more information would be helpful if people are to offer assistance!
Additionally, this has been covered before both on this forum and DJI Spark community.
Yes there is a way to change from 2.4ghz to 5.8ghz and vice versa.