async fn fetch_tx_size_cost_per_byte(&self) -> anyhow::Result<u64> {
        let mut auth_query_client = AuthQueryClient::new(self.grpc_channel.clone());
        let response = auth_query_client.params(QueryAuthParamsRequest {}).await;

        let params = response
            .map_err(|status| {
                anyhow::format_err!(
                    "failed to get auth params, code: {}, message: {}",
                    status.code(),
                    status.message()
                )
            })?
            .into_inner()
            .params
            .ok_or_else(|| anyhow::anyhow!("EmptyAuthParams"))?;

        Ok(params.tx_size_cost_per_byte)
    }
Fetches the transaction size cost per byte from the node.
core/node/da_clients/src/celestia/sdk.rs