[Vuejs]-Debugging VueJS Questionnaire – button not functioning

The problem says that you art trying to call forEach on undefined element. It points you to line 334 because there you have questionList.forEach.

Going through the Full code example, I noticed that you call onSendData on the click event, like:

 <button 
 ...
 v-on:click="onSendData(questionList)"
>

And because this is called in the template, I didn’t find something called questionlist (prop, data, computed, etc) to be actually passed as a parameter,
meaning what you are doing is similar to this:

 <button 
 ...
 v-on:click="onSendData()"
>

The reason enter works is probably because of <flow-form> and the events attached to that component.

So, instead of calling onSendData manually, you have to "force" the form submit event.

I would suggest if you do not intend to do anything special with that button, to leave the default one.