how to export glowing object from blender to ue4

your going to want to create a mask for the emissive. essentially you want a texture where everything is black exept the parts you want to glow those will be white.

how to export a glowing object or glowing parts of the same object, such as a glowing parts of a character and so on ?
in case i cant , can you suggest a solution on how to do this ?

i cant seem to understand , can you explain more ? or recommand a tutorial ? (i use blender just in case)

the simplest answer would be to UV-unwrap your model and export the uv layout.import the texture into a image editing software and find the sections you want to glow and paint those white and have the rest black.

once you have the mask you will need to import it into unreal and use it to control the emissive in a material.

my horrible quick guide:

There are other more proper ways to accomplish the same thing but those involve baking and would be a little more complex. to learn more about blender in general look up blenderguru on youtube.