Change Location in Runtime

AddressableAssets.cs

public static class AddressableAssets
{
    /// <summary>
    /// replace "BASE_URL"
    /// </summary>
    static string BaseUrl = "";

    public static void Init(string baseUrl)
    {
        BaseUrl = baseUrl;
    }

    static string CustomTransform(IResourceLocation location)
    {
        return location.InternalId.Replace("BASE_URL", BaseUrl);
    }

    [RuntimeInitializeOnLoadMethod]
    static void SetInternalIdTransform()
    {
        Addressables.InternalIdTransformFunc = CustomTransform;
    }
}

Sample.cs

public class Sample : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        AddressableAssets.Init("http://localhost:8000");
    }
}