I want to make running video, and I have done the left parts, how to copy and flip / invert key frame animation to right parts?

Hi,
thank you very much for your support request.

Here is my workflow:

1. Under "Animation" (pose editor) set "Auto Key" to "Generate".
   
2. Go to the first key frame of your left leg bones.
3. Select the left leg bones.
4. Use the "Copy to Other Side" button (pose editor --> tools) to copy the left leg bones animation to the right.
5. Move to the next key frame of your left leg bones and repeat step 4.
6. Then you need to offset the keys of your right leg bones by the half duration of your run cycle.

Please let me know in case you have any follow-up questions.

Best regards,
Peter