Here is the script you'll need:

This one goes in the site wide code injection (footer) - 'Settings > Advanced > Code Injection > Footer'

<script>
var acc = document.getElementsByClassName("accordion");
var i;
for (i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function() {  
this.classList.toggle("active");  
var panel = this.nextElementSibling;  
if (panel.style.display === "block") {    
panel.style.display = "none";  
} else {   
panel.style.display = "block";  }});}
var acc = document.getElementsByClassName("accordion");
var i;
for (i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function() {  
this.classList.toggle("active");  
var panel = this.nextElementSibling;  
if (panel.style.maxHeight) {    
panel.style.maxHeight = null;  
} else {    
panel.style.maxHeight = panel.scrollHeight + "px";  }});}
</script>

Then you'll need to add this in a Code Block on the page where you would like your FAQ accordion to appear:

<button class="accordion">QUESTION HERE</button>
<div class="panel">
<p>ANSWER HERE</p>
</div>

Lastly place the CSS in the Custom CSS section 'Design > Custom CSS'

.accordion { 
background-color: #525252; 
color: #fff; 
border: solid 1px #fff; 
cursor: pointer; 
padding: 18px; 
width: 100%; 
text-align: left; 
transition: 0.4s;
}

.accordion:hover { 
background-color: #ccc;
}

.panel { 
padding: 0 20px; 
background-color: #fff; 
max-height: 0; 
overflow: hidden; 
transition: max-height 0.4s ease-out;
}

Try changing the font weight, colour and sizing, you'll find more info on CSS and text at w3 Schools

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