How to reflect Skybox???

Hallo dear Community,

my Chef bought a Plugin called Spacebox mono (SpaceBox Mono in Blueprints - UE Marketplace), but if you try to make a Glossy surface in the level, it reflects only the “Standard Sky” from unreal, and I cant make it reflect the texture of spacebox mono. If I delete the “Standard Sky” the reflection vanishes, and I can only see the reflection of the near objects, but no sky at all… what can I do? I tried to make a Box Reflection Capture and to apply an SLS Specified Cubemap, but even that I managed to make a dds File and import it, I cant assign it as a reflection… HELP!!!
Thx

Add a SkyLight and set it to render a specified cubemap, select your skybox.