Custom workouts how can i enable the edit repetitions count screen?

Hi all, 

I may be asking a silly question, although to put you in context, I remember I could create a simple customs workout like Push-ups, and at the end of each step I was able to edit the repetition count with a fenix 6 pro. However, now I cannot find the way to do it on my fenix 7x.

Can anyone give me some advice about how I need to create a workout, what type of activity, etc, in order to be able to edit the repetition count at the end of each step?

Example of workout would be:

Warm-up : jumping jacks

Step 1: sits-up

Steps 2: push-up

Step 3: diamond push-up

End work out

Thanks