Optimisation of google api requests to retrieve data from youtube videos - optimization

Question

I'm trying to build a website with a section that displays the last video of a youtube channel and the thumbnails and titles of the next 9 most recent videos. The problem I'm having is that I consume the quota of requests just by testing the website.
To get this information I use Google's API. I retrieve the last 10 videos of the channel as follows:
<?PHP
include('global_variables.php');
$randomNumber = rand(2,10);
$randomKey = "api.key$randomNumber";
$data = file_get_contents("https://www.googleapis.com/youtube/v3/search?key=".$GLOBALS['api_key']."&part=snippet&channelId=".$GLOBALS['channel_id']."&order=date&maxResults=".$GLOBALS['videos_in_playlist']);
$json = json_decode($data);
echo $data;
?>
I call this PHP file in these ways:
// TO LOAD PLAYING YOUTUBE VIDEO
function loadVideo(iframe) {
$.getJSON("load_playing_video.php",
function(data) {
var videoNumber = (iframe.getAttribute('vnum') ? Number(iframe.getAttribute('vnum')) : 0);
iframe.setAttribute("src", "https://youtube.com/embed/" + data.items[videoNumber].id.videoId+ "?controls=1&autoplay=1&color=white");
// PLACE VIDEO TITLE
$("#playing-video-title").html(data.items[videoNumber].snippet.title);
// PLACE VIDEO DESCRIPTION
$("#playing-video-description").html(data.items[videoNumber].snippet.description);
}
);
}
loadVideo(document.querySelector("#playing-video"));
// TO LOAD THUMBNAILS AND TITLES ON SIDEBAR
$.getJSON("load_playing_video.php",
function(data) {
for (var index = 0; index < <?php echo $GLOBALS['videos_in_playlist']?>; index++) {
var videoImage = data.items[index].snippet.thumbnails.default.url;
var title = data.items[index].snippet.title;
var imgId = "#playlist-thumbnail" + index;
var titleId = "#playlist-title" + index;
document.querySelector(imgId).setAttribute("src",videoImage);
document.querySelector(titleId).innerHTML = title;
}
}
);
I was hoping someone could help me optimise the number of requests I do.
And if someone knows how I could increase the quota of requests (even if I have to pay) I would really appreciate some guidelines.
Thank you!!