You are awesome. Thank you. It works. The challenge now is my survey is already active. I cannot edit the logic anymore. How can I edit the survey and add the logic? I can do it after midnight so the impact is small. My worry is whether i will lose my previous responses by editing it. And also, the link must remain unchanged after editing the survey.

Urgently need your help.

I cannot edit the logic anymore.

Why not? You can edit question logic on an activated survey. The only way you will loose data is if you deactivate.

It is not editable. The Logic section of the question has been Read only. See screenshot attached.

I have never seen that. What LimeSurvey version are you using?

It looks like

LimeSurvey
Version 3.0.5+180118

I also attached a screenshot of the version below.

How should I do this then ?

Sorry, I don't have an answer other than updating to the latest version but that may not be wise while running an active survey.

Note: Always make sure to back everything up before updating.