Load an AssetReference

The AssetReference class has its own load method, LoadAssetAsync:

using UnityEngine;
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.AsyncOperations;

internal class LoadFromReference : MonoBehaviour
{
    // Assign in Editor
    public AssetReference reference;

    // Start the load operation on start
    void Start()
    {
        AsyncOperationHandle handle = reference.LoadAssetAsync<GameObject>();
        handle.Completed += Handle_Completed;
    }

    // Instantiate the loaded prefab on complete
    private void Handle_Completed(AsyncOperationHandle obj)
    {
        if (obj.Status == AsyncOperationStatus.Succeeded)
        {
            Instantiate(reference.Asset, transform);
        }
        else
        {
            Debug.LogError("AssetReference failed to load.");
        }
    }

    // Release asset when parent object is destroyed
    private void OnDestroy()
    {
        reference.ReleaseAsset();
    }
}

You can also use the AssetReference object as a key to the Addressables.LoadAssetAsync methods. If you need to spawn multiple instances of the asset assigned to an AssetReference, use Addressables.LoadAssetAsync, which gives you an operation handle that you can use to release each instance.