Hello, thank you for getting in touch and for your support!
Just to avoid any confusion, Unity makes used of built-in shaders known as
Standard Surface Shaders, and ASE allows you to create this shader type, as well as
Custom Shaders through Templates, which provide the means to do things that a surface shader can't.
Our Sprite Template does not offer an emissive port as a standard surface shader would, however, you can still achieve a glow effect without having to resort to it, by simply multiplying a color value to it, for example.
I'll need you to share more details regarding what you intend to create in order to best help you out, since if you specifically need to use the Sprite Template it might be best to either resort to a post processing effect for the glow, or to a sprite effect similar to the ones used in our UISpriteFX sample.
Looking forward to your reply!