@MarijaiNikola 

Tapo automations don’t support loop triggering -- that means any state change triggered by an automation won’t start another automation.

If you need a device to turn on and off repeatedly, you’ll have to add each step of the cycle (on and off) as separate actions within the same automation.

  @MarijaiNikola 

I'm afraid there are no simple settings to meet your needs. As mentioned earlier, if you need the plug to cycle on and off repeatedly, you can add each step separately in the automation -- that means adding one action for each time you want it to turn on or off. Between each action, you can insert a “Delay” action to set the desired interval.

For example:

• Turn on plug
• Delay 3 minutes
• Turn off plug
• Delay 12 minutes

…then repeat these four steps as needed. Up to 64 actions can be added in a single automation entry.