Need help coding a simple break

[cquimpo]

Hello, I am a research assistant. Our lab professor would like us to code a break for the users at the halfway point of the experiment that we are coding. I am not very well versed in code and after looking at grammar references for a couple of hours, I gave up. Does anyone have a format to code this kind of function? Thanks in advance.
Example:
6 Questions
Answer Question 1
Answer Question 2
Answer Question 3
*insert mandatory 15-second break with a screen that says something like "this is a mandatory break, please take a second to look away from the screen."
Answer Question 4
Answer Question 5
Answer Question 6
Finish
This is our current code:
Trial Template: 
{
  "Instr":{"type": "instruction",
        "stimuli": ["TrainingInst"],
        "duration": 10
      },
  "Trial1": {
    "type": "basic",
    "stimuli": ["video1","video2","video3","video4","video5","video6","video7","video8","video9","video10","video11","video12","video13","video14","video15","video16","video17","video18","video19","video20"],
    "response_pairing": "alternate",
    "stimulus_pattern": {"order": "random"},
    "responses": ["1R","2R","3R","4R","5R","6R","7R","8R","9R","10R","11R","12R","13R","14R","15R","16R","17R","18R","19R","20R"],
    "delay": 3
  }
}

Procedure:
{
    "type": "blocking",
    "blocks": {
      "TrialBlock": {
        "trial_templates": ["Trial1"],
        "cover_trials": ["Instr"]
      }
    },
    "block_sequence": ["TrialBlock"]
}