@guidovh 

Tapo plug does not support infinite loop switching, whether through smart plug's own function or automation. 

If the time interval for each loop operation is long, or doesn't need a infinite loop, you might consider using multiple on&off actions combined with the delay action in one automation to achieve such scenes. Up to 64 actions can be added in one automation. How to create Smart Action (Automation or Shortcut) on Tapo app

E.g.

[When] Smart plug turn on

[Then] 

1. Smart plug Remain on for 1 minute

2. Delay 1 minute

3. Smart plug (turns on and) Remain on for 1 minute

4. Delay 1 minute

<Repeat....>