A flying wing needs mixer setting up in your radio for Aileron and Elevator to work correctly. Using flight controller you might not need to worry about this, but without an FC you’ll have to set this up manually.
Depending on what radio you have, the setup process can be different.
For Spectrum, simply go to wing tail mix and activate ‘Elevon’.
For Flysky i6: go to Functions menu -> Elevons and activate them.
If you are using Taranis, or other OpenTX loaded transmitter, it’s slightly more complicated than other systems, as you’d have to do this manually.
That’s it, if you want more detail, check out Flitetest’s video:
Let me know if you have any questions.