Why NestJS microservice runs on TCP, meanwhile API gateway runs on TCP6

Question

I'm trying to connect my Nestjs microservice to the API gateway but from what I see with command: netstat -tunlp The API gateway runs on: tcp6 0 0 :::3000 :::* LISTEN 55235/node

Meanwhile the microservice: tcp 0 0 0.0.0.0:3100 0.0.0.0:* LISTEN 55225/node

When I try to log the client on the API gateway I get this:

1|api  | ClientTCP {
1|api  |   routingMap: Map(0) {},
1|api  |   logger: Logger { context: 'ClientTCP', options: {} },
1|api  |   isConnected: false,
1|api  |   port: 3100,
1|api  |   host: 'localhost',
1|api  |   socketClass: [class JsonSocket extends TcpSocket],
1|api  |   serializer: IdentitySerializer {},
1|api  |   deserializer: IncomingResponseDeserializer {},
1|api  |   onApplicationShutdown: [Function: close]
1|api  | }

Could the TCP/TCP6 be the issue? If yes, how could I bypass this?

I was hoping for it to connect to the microservice, but nothing happens.