How can I store a div element's text values to string variable then check if this string contain a word

Question

<div class="address">
firstname lastname<br>company<br>vat number<br>postcode<br>1000 street<br>Country<br>05324324
</div>

// let template = document.querySelector('.address').value;

I need the div's all text to store a variable, then check this variable contain a word (for example postcode) then return boolean true or false