Public Sprite image help

I am making a Quiz Game but with images. I am able to make a question only quiz game but I want the game to have images also but I don’t know where to apply the “sprite” field.
For example:
I have Question.Text for which I am able to use a text UI and it works perfectly fine but when I try to use Question.sprite, it doesn’t work saying that UnityEngine.sprite doesn’t exist

Without your actual code, one can only guess, but have you written “sprite” like in your question? The actual class is “Sprite” with an uppercase S.

Sprite is a property that SpriteRenderer and Image have.
Then, if you want change an sprite selecting from the resource folder do this:

//SpriteRendere example
public Image _questionImage;
public Text _questionText;

private void DoWork()
{
      //Remember that you need a folder called "Resources" inside of the Assets folder
      _questionImage.sprite = Resources.Load<Sprite>("MyFolder/MySprite");
      _questionText.text = "MyText";
}

MyFolder
Is the folder (If you want create it) inside of Resource Folder.

MySprite
Is the sprite name. Of course is inside in MyFolder.