Move multiple keyframe

Hello. I have build a fairly complex animation.

I need to insert something at the beginning of this animation. To this I will need to slide all the animation down.

How can I move all my animation down on the timeline? Thanks.

create keyframe and move anchor, That drags the frames
wiki.synfig.org/Keyframe

Thanks for the response. On the file in question this technique does not work. Could that fact that I had deleted all the default keyframe (0f) during my process have something to do with that?

However this technique seems to work on a new file where I had several objects animated where I had not deleted the default keyframe (0f).

Thanks for the tip.