question

I figured it out thanks to an answer on a different question.

Here's my (simplified) code to call ExecuteFunction from Unity editor (not playmode/runtime).

public static async void CallCloudScriptEditorTime(string somePlayfabID)
    {
        var isDone = false;
        var entityToken = "";
        PlayFab.AuthenticationModels.EntityKey entity = null;

        PlayFabAuthenticationAPI.GetEntityToken(
            new PlayFab.AuthenticationModels.GetEntityTokenRequest(){}, 
            (result)=>{
                isDone = true;
                Debug.Log(result.EntityToken);
                entityToken = result.EntityToken;
                entity = result.Entity;
            },
            (error)=>{
                isDone = true;
                Debug.Log(error.GenerateErrorReport());
            }
        );

        while (!isDone)
        {
            await Task.Delay(1000); 
        }

        PlayFabCloudScriptAPI.ExecuteFunction(new ExecuteFunctionRequest() {
            AuthenticationContext = new PlayFabAuthenticationContext("",entityToken,somePlayfabID,entity.Id, entity.Type),
            Entity = new PlayFab.CloudScriptModels.EntityKey() { Id = entity.Id, Type = entity.Type },
            FunctionName = "MyFunction",
        }, (result) => {
            // Do something with result
        }, (error) => {
            // Error
        });
    }

link to the other question: https://community.playfab.com/questions/56881/calling-playfabcloudscriptapiexecutefunction-with.html