JScript help

[lucifer]

Spoiler: The Script

<script type="text/javascript">
$(function() {
$('.marquee').marquee({
duration: 5000,
startVisible: true,
duplicated: true
});
});

function play(audio, name) {
audio.play();
document.getElementById("playingnow").textContent = name;
return new Promise(function(resolve, reject) {
audio.addEventListener('ended', resolve);
});
}

function startmusic() {
var audio1 = new Audio('assets/music/omendarklight.mp3');
var audio2 = new Audio('assets/music/cravethedirt.mp3');
var audio3 = new Audio('assets/music/egodeath.mp3');
var audio4 = new Audio('assets/music/hatesong.mp3');
var audio5 = new Audio('assets/music/madonna.mp3');
var audio6 = new Audio('assets/music/moveslowly.mp3');
var audio7 = new Audio('assets/music/nothingleft.mp3');
var audio8 = new Audio('assets/music/protecther.mp3');
var audio9 = new Audio('assets/music/takethecharge.mp3');
var audio10 = new Audio('assets/music/alone.mp3');
play(audio1, "omenxiii - dark light").then(function() {
return play(audio2, "velvetears - crave the dirt");
}).then(function() {
return play(audio3, "lilbootycall - ego death");
}).then(function() {
return play(audio4, "wifisfuneral - disdahatesongbby");
}).then(function() {
return play(audio5, "yung bambi x kamiyada+ - madonna");
}).then(function() {
return play(audio6, "velvetears - move slowly");
}).then(function() {
return play(audio7, "despair - when you have nothing left");
}).then(function() {
return play(audio8, "kamiyada - someone protects her");
}).then(function() {
return play(audio9, "prescription - takethecharge");
}).then(function() {
return play(audio10, "downtime - alone");
}).then(function() {
return play(audio1, "omenxiii - dark light");
});
}

startmusic();
</script>

I'd like this script to have a volume control to be permanently set to a value, like 20% or so.

I tried using this:

Spoiler: Volume Script

<script>
var video = document.currentScript.parentElement;
video.volume = 0.25;
</script>

However this only tends to work with my old HTML page and the <audio> tag.
The only reason I'm using this script is that the site was made (well-made at that) by a fellow user here on MCM, and it lists the names of the songs as requested with the job.

I would try StackOverflow, but I neeever get replies there, so I'm coming to you all. Please PM me if you're able to help!

Site link if needed:
https://mystie.co/

PS: Don't worry about the marquee part in the script. That's there for a reason, haha.