Intall plugin from Unreal Engine Marketplace

https://www.unrealengine.com/marketplace/ja/product/facemotion3d-plugin

1. import the FBX file you wish to move.

　Sample avatars are available below, please create 52 morphs using the sample avatars as reference.

 https://drive.google.com/drive/folders/1iX1_4exoGIk0ReSYc2QZL9C0NBo-P9Nf?usp=share_link

2. right-click in the content browser and select Animation→Animation BP.

　Select the skeleton of the FBX file you loaded.

3. Double-click on the Animation BP you created.

4. Within the Animation BP, right-click and search for "FACEMOTION3D".

5. Connect the FACEMOTION3D plug-in to the output pose.

6. In FACEMOTION3D plug-in, open Settings→Send Settings and turn ON "Is Send Message".

　Enter the IP address of the iPhone in the "Send IPAddress" field and press the "Send Start Message" button.

7.Then the iPhone app and UnrealEngine will be connected. 

8. The name of the bone to be moved can be set in the iOS app.

　Go to Settings -> Streaming Settings and open the UnrealEngine tab.

　Enter the name of the bone you want to move.

9. If you want to ignore the iOS app's bone name setting and specify the bone name on the UnrealEngine side, turn on Settings→Use UE4Bone Name in the FACEMOTION3D plug-in.

　Then, the bones will work with the bones specified in UnrealEngine's HumanoidRig.