在请求Access Token时，应该在请求中携带Client Secret，并用Base64进行编码。以下是代码示例：

// Base64编码方法 function base64_encode(str) { var base64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

var input = escape(str);
var output = "";
var char1, char2, char3 = "";
var enc1, enc2, enc3, enc4 = "";
var i = 0;

do {
    char1 = input.charCodeAt(i++);
    char2 = input.charCodeAt(i++);
    char3 = input.charCodeAt(i++);

    enc1 = char1 >> 2;
    enc2 = ((char1 & 3) << 4) | (char2 >> 4);
    enc3 = ((char2 & 15) << 2) | (char3 >> 6);
    enc4 = char3 & 63;

    if (isNaN(char2)) {
        enc3 = enc4 = 64;
    } else if (isNaN(char3)) {
        enc4 = 64;
    }

    output = output +
    base64_chars.charAt(enc1) +
    base64_chars.charAt(enc2) +
    base64_chars.charAt(enc3) +
    base64_chars.charAt(enc4);
    char1 = char2 = char3 = "";
    enc1 = enc2 = enc3 = enc4 = "";
} while (i < input.length);

return output;

}

// 请求Access Token方法 function requestAccessToken(clientId, clientSecret) { var url = "https://oauth.example.com/token"; var data = { "grant_type": "client_credentials", "client_id": clientId }; var headers = { "Authorization": "Basic " + base64_encode(clientId + ":" + clientSecret) };

$.ajax({
    url: url,
    type: "POST",
    data: data,
    headers: headers,
    success: function(response) {
        console.log(response.access_token);
    },
    error: function(error) {
        console.log(error);
    }
});

}

// 使用示例 requestAccessToken("your_client_id", "your_client_secret");