From my JavaScript client, I send the JSON data using POST method

fetch("https://%$%$%%$.azurewebsites.net/api/JointPose?", {
                    method: "POST",
                    body: JSON.stringify({
                        JointPose1: `${Joint1Pose}`,
                        JointPose2: `${Joint2Pose}`,
                        JointPose3: `${Joint3Pose}`,
                        JointPose4: `${Joint4Pose}`,
                        JointPose5: `${Joint5Pose}`,
                        JointPose6: `${Joint6Pose}`,
                        JointPose7: `${Joint7Pose}`
                    }),
                    headers: {
                        "Content-Type": "application/json; charset=UTF-8",
                    }
                })
                    .then(response => {
                        if (!response.ok) {
                            throw new Error('Network response was not ok ' + response.statusText);
                        }
                        return response.json();
                    })
                    .then(data => {
                        console.log('Success:', data);
                    })
                    .catch(error => {
                        console.error('Error:', error);
                    });

I try to retrieve the request body using HTTPtrigger in my Azure Functions app

public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = "JointPose")] HttpRequest req)
        {
            MemoryStream ms = new MemoryStream();
            await req.Body.CopyToAsync(ms);
            string jointPoseData = ms.ToString();

            //using StreamReader reader = new(req.Body);
            //string bodyStr = await reader.ReadToEndAsync();
            //var jointPoseData = JsonConvert.DeserializeObject<JointPoseData>(bodyStr);

            return new OkObjectResult( new { Content = new StringContent(JsonConvert.SerializeObject(jointPoseData), Encoding.UTF8, "application/json") });
        }

public class JointPoseData
    {
        public string JointPose1 { get; set; }
        public string JointPose2 { get; set; }
        public string JointPose3 { get; set; }
        public string JointPose4 { get; set; }
        public string JointPose5 { get; set; }
        public string JointPose6 { get; set; }
        public string JointPose7 { get; set; }
    }

The response I get after opening the URL is

When opened the URL link in browser

Expected output is:

JointPose1: 0.31, JointPose2: 0.32,…….

I think the jointPoseData is null. How do I retrieve the request body with appropriate values?