make a Put http request with Angular12 and ASP.NET Core REST API (example: reset notification count)

Question

This is the service in angular : I get the OnlineUser from the component, here i can't connect to APi :

private baseUrlRemoveNotifications: string =
   "api/v1.0/UploadDownload/removeNotifications";  
public removeNotificationForUser(onlineUserModel: OnlineUserModel) {
   let username = onlineUserModel.userName;
   console.log("send remove.............");
   const url = `${this.baseUrlRemoveNotifications}`;
   const options = {
     headers: new HttpHeaders({
       "Content-Type": "application/json",
     }),
   };
   return this.http.put(
     `${this.baseUrlRemoveNotifications}`,
     username,
     options
   );
 }

My API in .Net core When i debugger i can't reach the api is here some mistakes... if possible how can i remove the result from the reducer to update the state of notification and thank you ...

   [HttpPut("[action]")]
        [Route("removeNotifications")]
        public async Task<IActionResult> RemoveNotifications([FromBody] string username)
        {
            try
            {
                var sender = await _userManager.FindByNameAsync(username);
                var reciever = await _userManager.FindByNameAsync(User.Identity.Name);
                // My Methode to update Notification Table => change Iseen column to true //
                return Ok("Success");
            }
            catch (Exception ex)
            {
                Log.Error("An error occurred while seeding the database  {Error} {StackTrace} {InnerException} {Source}",
                   ex.Message, ex.StackTrace, ex.InnerException, ex.Source);
            }
            return BadRequest("Failed");
            
        }