Why am I getting "Multiple possible networks found, use a Network ID to be more specific" error in CloudForms 3.0?

Issue

I need your help to launch an instance with OpenStack. I successfully added the OpenStack provider to CloudForms, I can see the existing instances, flavors, etc. When I launch an instance, the process stops with error:

Excon::Errors::BadRequest]: Expected([200, 202]) <=> Actual(400 Bad Request) response => #<:response:0x0000000f314a20>"{\"badRequest\": {\"message\": \"Multiple possible networks found, use a Network ID to be more specific.\", \"cod

There are multiple networks in the OpenStack environment. I can't see any option to choose the network for the instance. How can I solve this problem