"Click to enlarge" an image - Problem resizing the image

Hi there!
I am trying to find a way for respondents to click and enlarge images, and then go back to the survey.
My images are directly within question labels.
I tried using the code mentionned on that post: https://community.qualtrics.com/XMcommunity/discussion/821/how-do-i-allow-respondents-to-click-to-enlarge-an-image
In both cases, I am now able to enlarge the image but unable to go back to the survey (there is no "X" to go back to the normal size, unlike the example in the post).
Does anyone have an idea what I'm doing wrong? I am not a programmer so I'm a bit confused here 😓 Any help is welcome!