code snippet - Uploading to the Steam Workshop (by Jeremy Wolf, one wheel studio, src: https://onewheelstudio.com/blog/2020/12/3/steam-workshop-with-unity-and-facepunch-steamworks)

SteamWorkshopUploadSnippet.cs

private static async Task UploadLevelToSteamWorkshopAsync(string levelName)
{
    Debug.Log("Uploading...");
    
    //app data path is to the folder
    //my files are stored in a folder with the same name as the level name
    string appDataPath = ES3Settings.defaultSettings.FullPath;
    appDataPath = appDataPath.Replace("SaveFile.es3", levelName);
    
    //the preview path is to the image file
    //I used jpeg for a smaller file size
    string previewPath = appDataPath + "/" + levelName + ".jpeg";
    
    WML Specific bits
    
    var result = await Steamworks.Ugc.Editor.NewCommunityFile
                        .WithTitle(levelName)
                        .WithDescription(description) // the description is just a string
                        .WithTag("Level")
                        .WithTag("Beta")
                        .WithContent(appDataPath)
                        .WithPreviewFile(previewPath)
                        .WithPublicVisibility()
                        .SubmitAsync(new ProgressClass());

    Debug.Log("Successfully Uploaded:" + result.Success + " Needs Agreement: " + result.NeedsWorkshopAgreement);
    
    if (result.Success == false)
    {
        ErrorMessage.ShowErrorMessage("Upload of Files Failed... Please Let the developer know.");
        uploadFailed?.Invoke();
    }
    
    wml specific bits
}

thoughts.md

This gist is just code from an image from the linked post, copied into text by hand. It is prone to human error and there may be inconsistencies between the gist and the image.