We will be demonstrating how you can set a background for a text component, but the same method applies to buttons as well.
Start by clicking on the image/button component on the canvas that you would like to customise the background for. The corresponding properties will open to the right of the canvas.
Click on Design tools.
Under Background, you will see a dropdown with 2 options:
Setting a solid colour as the background
From the Background dropdown, under design tools, select Colour.
Next, click on the colour block just below to select your desired colour for the background.
Set an Image as the background
From the Background dropdown, under design tools, select Image.
Then, click on Upload Image.
In the pop-up that appears, you can either:
Select an Image from the recently uploaded images.
Click on Done to confirm.
Or, you can click on Upload and select an image from your files.
Once uploaded it will be visible in the Media Gallery. Click on Done to confirm.
4. Once your Image is selected, you can adjust the relative position from the corresponding dropdown.
5. Select Fit, Fill or Tile and from the adjacent dropdown select the relative Image frame.