How to add text watermark to image using PHP - php

Question

here i am doing multiple image upload , user select the images and click the submit button means i want add watermark in that images after that i have to move the images in temporary folder,except adding water into the image i have completed, i don't know i how to add water mark in image , if anyone know means please update my answer
$("#rentBtnSubmit").click(function(e){
e.preventDefault();
var formData = new FormData();
var formData = new FormData($('#rentForm')[0]);
formData.append('file[]', $('input[type=file]')[0].files[0]);
$.ajax({
type:'POST',
url :"test.php",
data: formData,
cache: false,
contentType: false,
processData: false,
success: function(data) {
if(data['status'] =='success'){
alert('Success');
}
else{
alert('Error');
}
},
error:function(exception){
$("#rentError").show();
$("#rentError").fadeOut(4000);
}
});
});
<form id="rentForm">
<div class="row">
<div class="col-md-12">
<div class="form-group">
<label class="control-label">Upload Property Photo</label>
<br>
<div id="maindiv">
<div id="formdiv">
<span id="filediv col-md-3"><input name="file[]" type="file" id="file" multiple=""/></span>
</div>
</div>
</div>
</div>
</div><br><br>
<button type="button center-block" id="rentBtnSubmit">Submit</button>
</form>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
test.php
$FilleAll = $_FILES['file']['name'];
$fileCount = count($FilleAll);
for ($i = 1; $i < count($FilleAll); $i++) {
$extension = pathinfo( basename($_FILES['file']['name'][$i]), PATHINFO_EXTENSION);
$image_filename= md5(basename($_FILES['file']['name'][$i]).time()).'.'.$extension;
$move = move_uploaded_file($_FILES['file']['tmp_name'][$i],"watermark_images/".$image_filename);
}