How to set AmbientColor in MDL material?

I tried to create a material with MDL recently. I didn’t find the corresponding parameter of Ambient Color in MDL material struct. Can someone tell me how to do it?

MDL is a language to describe physically based materials and therefore has no notion of “Ambient color” Any real world material would react to ambient light the same way it reacts to any other light. Renderers that use an ambient light term should just pick up the color of the diffuse components in an MDL material and use that color.