5.2.1.Get Ready To Rig
1. Choose Anim Blueprint Class for your character.
2. Drag your skeletal mesh to the scene.
For SK_Mannequin you can use ManRig preset from examples project for reference.
3. Select character and press Rig button.
If everything goes well you will see a yellow circle under the character. This circle is a Main controller. All other controllers will be attached to it. Try to move this controller to make sure that it drives the character.
4. Select Main Controller and press DeleteRig button.