Getting twitter user timeline



Hello I am new at twitter developers api I want to pull twitter twits from their user name . I have found one api
I have created app from and got token client it etc , but I getting error in passing all this data in header request my code is

 return $.ajax({
                url: '',
                method: 'GET',
                headers: {
                    'Accept': 'application/json',
                    'Access-Control-Allow-Methods': "*",
                    'Authorization': `OAuth oauth_consumer_key="XXXXX",oauth_token="XXXXXX-XXXX",oauth_signature_method="HMAC-SHA1",oauth_timestamp="1503397884",oauth_nonce="8yZNhMxt9A1",oauth_version="1.0",oauth_signature="BUGLYJrM40UKN0LQNcPmfsyUIg8%3D"`
            }).then(function (data, status, headers, config) {
            .catch(function (err) {

I get user twitter on POSTMAN app
But this not working for me by doing code ,so any one can suggest me how can I get this