RelayUtility.cs

using System;
using System.Threading.Tasks;
using Unity.Services.Relay;
using Unity.Services.Relay.Models;
using UnityEngine;

public class RelayUtility
{
    public static async Task<(string ipv4address, ushort port, byte[] allocationIdBytes, byte[] connectionData, byte[] key, string joinCode)> AllocateRelayServerAndGetJoinCode(int maxConnections, string region = null)
    {
        Allocation allocation;
        string createJoinCode;
        try
        {
            allocation = await Relay.Instance.CreateAllocationAsync(maxConnections, region);
        }
        catch (Exception e)
        {
            Debug.LogError($"Relay create allocation request failed {e.Message}");
            throw;
        }

        Debug.Log($"server: {allocation.ConnectionData[0]} {allocation.ConnectionData[1]}");
        Debug.Log($"server: {allocation.AllocationId}");

        try
        {
            createJoinCode = await Relay.Instance.GetJoinCodeAsync(allocation.AllocationId);
        }
        catch
        {
            Debug.LogError("Relay create join code request failed");
            throw;
        }

        return (allocation.RelayServer.IpV4, (ushort)allocation.RelayServer.Port, allocation.AllocationIdBytes, allocation.ConnectionData, allocation.Key, createJoinCode);
    }

    public static async Task<(string ipv4address, ushort port, byte[] allocationIdBytes, byte[] connectionData, byte[] hostConnectionData, byte[] key)> JoinRelayServerFromJoinCode(string joinCode)
    {
        JoinAllocation allocation;
        try
        {
            allocation = await Relay.Instance.JoinAllocationAsync(joinCode);
        }
        catch
        {
            Debug.LogError("Relay create join code request failed");
            throw;
        }

        Debug.Log($"client: {allocation.ConnectionData[0]} {allocation.ConnectionData[1]}");
        Debug.Log($"host: {allocation.HostConnectionData[0]} {allocation.HostConnectionData[1]}");
        Debug.Log($"client: {allocation.AllocationId}");

        return (allocation.RelayServer.IpV4, (ushort)allocation.RelayServer.Port, allocation.AllocationIdBytes, allocation.ConnectionData, allocation.HostConnectionData, allocation.Key);
    }
}