how can use jira cloud api in jira

RS Software

i am not able to get api value from jira using ajax call please help me

 

Failed to load http://rssoftware.atlassian.net/rest/api/2/user?username=TonmoyS: Response for preflight is invalid (redirect)

RS Software

<html>
<head>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
var settings = {
"async": true,
"crossDomain": true,
"url": "http://rssoftware.atlassian.net/rest/api/2/user?username=TonmoyS",
"method": "GET",
"headers": {
"Accept": "application/json",
"Authorization": "Basic xxxxxxxxxxxx",
"Cache-Control": "no-cache"

}
}

$.get(settings).done(function (response) {
alert(response);
});

});
</script>
</head>
<body>

</body>
</html>