https://flippednormals.com/downloads/face-rigging-in-blender-tutorial/

In the begging, after a small introduction to Face Action Coding system and some advice on organizing the work, I will walk you through the process of sculpting necessary expressions. I’ll show you how to utilize references, and give some tips and tricks on forming the face, managing stretches and sculpting important wrinkles. In the sculpting process I will be using ZBRUSH, but after some minor workflow adjustments you can without a problem do it in BLENDER (I show how to sculpt realistic face just in Blender in my “Realistic Face Creation in Blender” course.

Afterward, we will take all of the expressions sculpted in Zbrush and implement them to the face rig. Face deformations will be made by shape keys driven by the bones. Moreover, we will use high detail information made in Zbrush to create Dynamic Wrinkle System in Eevee (it works in Cycles as well).
Then I’ll show you how to make your animation work way more convenient, by creating puppeteering systems for a more intuitive animating process.
In the end, I’ll present to you, how to prepare your rig for the export to Unreal Engine. And how to set up the Dynamic Wrinkle system in it as well.