Animation restarts from the begining

I’m new in UE4. I 've imported a walking animation from Mixamo for my character in the sequencer and I would like that my character do more steps but each time that I try to extend the animation with cursor or if I just copy the same animation after the first one, the character restart from the original spot instead of continuing on from where he ended. :confused:
How can I extend my walking animation please ? Thank you.