How to apply borrowed normals through data transfer ?

I have data transfer modifier on an object. Normals are transferred perfectly. What’s next ? How can I apply the modifier to export the model into game engine ? Whatever I puch, apply or create data layer the normals turns back to original state.

Enable autosmooth in object data properties. The angle should be grayed out when it’s using custom normals data.

Yes, even after you have applied the modifier, it’s important to keep “Autosmooth” enabled for your object.
By example, here’s the same object, bottom in solid shading, left in smooth shading, right with smooth shading + custom normals (modifier applied) and autosmooth enabled

If i disable autosmooth for the right object, Blender does display the same kind of normal as the object to the left, if i re-enable autosmooth it give me back the custom normals

Thanks a lot guys. It’s right what I looked for