An error occurred while attaching module (Dynamicweb.Frontend.Content)

System.AggregateException: One or more errors occurred. ---> System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
   at System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)
   at System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)
   --- End of inner exception stack trace ---
   at System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult, TransportContext& context)
   at System.Net.Http.HttpClientHandler.GetRequestStreamCallback(IAsyncResult ar)
   --- End of inner exception stack trace ---
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at HCTTool.CustomModules.Services.ApiService.PostAsJson[T](String baseUri, String requestUrl, Object requestModel, String token, Boolean useCamelCaseOnProperty) in C:\Projects\Repos\HCT\HCTTool.CustomModules\Services\ApiService.cs:line 40
   at HCTTool.CustomModules.Services.DropShipment.DropShipmentService.SetDropShipmentProducts(List`1 products) in C:\Projects\Repos\HCT\HCTTool.CustomModules\Services\DropShipment\DropshipmentService.cs:line 34
   at HCTTool.CustomModules.Services.DropShipment.Notifications.DropShipmentProductBeforeRender.OnNotify(String notification, NotificationArgs args) in C:\Projects\Repos\HCT\HCTTool.CustomModules\Services\DropShipment\Notifications\DropShipmentProductBeforeRender.cs:line 27
   at Dynamicweb.Extensibility.Notifications.NotificationManager.Notify(String notification, NotificationArgs eventArgs)
   at Dynamicweb.Ecommerce.Frontend.Frontend.RenderProduct(Product product, String unitId)
   at Dynamicweb.Ecommerce.Frontend.Frontend.EcomRender()
   at Dynamicweb.Ecommerce.Frontend.Frontend.GetContent()
   at Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)
---> (Inner Exception #0) System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
   at System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)
   at System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)
   --- End of inner exception stack trace ---
   at System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult, TransportContext& context)
   at System.Net.Http.HttpClientHandler.GetRequestStreamCallback(IAsyncResult ar)
   --- End of inner exception stack trace ---<---