I’m new to using java script in Qualtrics and I have a question – maybe someone here can help me?

I’m running a study where participants are randomly allocated to read one of 16 vignettes. Of course, I could set this up using the survey builder and survey flow, but I would like to use code – this is a pilot study for a larger experiment with over 500 vignettes, which would be too complicated to set up manually.
What I think I need to do is to set embedded data fields with variable names for each vignette, and then tell Qualtrics the corresponding vignette text for each name. Next, I can use the survey flow to randomly assign one vignette to each participant.
I have never used java script before, so this is the code I scrambled together (it’s probably totally wrong):

`Qualtrics.SurveyEngine.addOnload(function() {
// Get the value of the selected variable from embedded data
var selectedVariable = “${e://Field/SelectedVariable}”;

// Define the vignettes with their corresponding text
var vignettes = {
    "aAA1BB1AB1BA1": "Text for vignette 1...",
    "aAA1BB1AB1BA0": "Text for vignette 2...",
    // Add more vignettes as needed
};

// Get the text for the selected vignette based on the selected variable
var selectedVignetteText = vignettes[selectedVariable];

// Set the text of the question to display the selected vignette
this.getQuestionTextContainer().innerHTML = selectedVignetteText;

});
`

Could somebody help me with this?

I entered the code above in the java script window for a text/ graphic question, but when I click preview it just says “undefined”.
I also tried to enter something similar into the html view in the rich text editor, but the code was never saved there and always disappeared.