How to access output from Crowd Entity Annotation

I'm creating a task on AMT using the Crowd entity annotation Elements that let reviewers label each word in a text block. I want to ensure that the reviewer selects a label for every word/character in the text before submitting the job. What I am trying is to use onsubmit and a validation function in the script section to check whether the length of the labeled entities added together is equal to the total length of the text block but I can't access the output of the crowd entity annotation. This is what I tried but failed:

const answers = document.querySelector('crowd-entity-annotation').value.entities 

I also tried this, which return 'undefined':

const answers = document.querySelector('crowd-entity-annotation').entities 

I appreciate any help.