gRPC section -- where should api_service.rs go?

[dan-seol]

Hello, thanks for the step-by-step tutorial! It;s been really helpful. I am learning so much from it.

I had a question:

https://rust-on-nails.com/docs/api/grpc/

Section Implementing our API End Point is telling me to create

pub struct UsersService {
    pub pool: Pool,
}

#[tonic::async_trait]
impl grpc_api::users_server::Fortunes for UsersService 
...

in crates/web-server/api_service.rs.

but in a later section Integrating Tonic and Axum

crates/web-server/src/main.rs should import use grpc_api::api::api_server::UsersServer;. Where is UsersServer coming from?
is users_service.rs used at all? I am a bit confused.

I am currently blocked on this, would you want to help me?