How can I get the vertex data of the arkit face mesh?

[Anonymous_40a6e9871154fced3092898ae3dee033 (四五六)]

https://docs.developer.apple.com/documentation/arkit/arfacegeometry
There are Mesh Data call parameters for accessing ARFaceGeometry in the Apple developer documentation.I need to get the vertex array through ue4. How can I do this?