I have created a variable in GTM code to fetch emails but It needs to collect the data from the thankyou page Script. I have used Zoho forms to do this. Can somebody help?

Here's the function I'm using:

function() { 
  try { 
    var searchEmail = function(input) { 
      for(i=0; i<input.length; i++) { 
        email = input[i].value; 
        if(email.match(/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i)) { 
          return email; 
        } 
       } 
    } 
    return searchEmail({{Form Element}}); 
  } catch(e) { 
    return ""; 
  } 
} 

The idea is that the code you put in on the thank-you page passes the emailInput variable to the script you put in the thank-you page.