How to implement Modbus TCP Server in dotnet 6 as an API application?

Question

.NET

I have an industrial 4G router (TCP Server, TCP Client modes) with a Serial Line connected to it (UDP, UDP Multicast, TCP Server, TCP Client modes, Modbus RTU Master, Modbus RTU Slave, Modbus ASCII Master, Modbus ASCII Slave, RealCOM_MCP, RealCOM_CCP, RealCOM_MW, Pair Connection Master, Pair Connection Slave, Httpd Client, WebSocket Client) and connected sensor via RS485.

If I select the Modbus RTU Slave mode, then I can connect and receive data from the sensor. But my situation is the opposite, I need to create a Modbus TCP Server to which the Serial Line will be connected.

I used the library https://github.com/NModbus/NModbus
I came across the fact that when creating an IHostedService I cannot connect to it, although through Netstat -a I see the IP address and port on which I created the server.

Who can explain how to make a Modbus TCP Server that will send and receive messages from sensors.