Web.Permissions Error - Plugin

Hello everyone,

i have a plugin out registered of the sandbox. It should be able to send some data to an external system. I set the endpoint as a static IP.

Error:

My code:

BasicHttpBinding myBinding = new BasicHttpBinding();
myBinding.Name = "BasicHttpBinding_IPOCService";
myBinding.Security.Mode = BasicHttpSecurityMode.None;
myBinding.Security.Transport.ClientCredentialType = HttpClientCredentialType.None;
myBinding.Security.Transport.ProxyCredentialType = HttpProxyCredentialType.None;
myBinding.Security.Message.ClientCredentialType = BasicHttpMessageCredentialType.UserName;

ChannelFactory<Interface> factory = new ChannelFactory<Interface>(myBinding, endPointAddress);
var client = factory.CreateChannel();

Thank you in advance for any advice :)