You have multiple options if you want a backdrop for your animation:

• redraw it every frame
• enable Allow Copy under the Extra tab and keep copying it to first layer
• use an image from another strip (by you or someone else)

—-

this tutorial shows how to make this third option to work:

the ANIM tab is visible if you are making an animation

under ANIM tab set:

Backdrop Strip ID ←—- id of the strip you want backdrop from (0 for no backdrop)

Image Index ←—- this is the image in the selected strip (1 is the first)

(for this tutorial we are using Electra's Free to use Backgrounds 2 )

Press 'Update' or 'Make Strip' to save your settings I reccomend setting the backdrop before drawing the first frame

Now when you start drawing the backdrop should show up on the canvas:

You can toggle the backdrop with this button:

The backdrop itself will only show up in the finished animation you can test it with the Show Anim button (but it will be only visible after you have at least 2 frames)

see the finished example animation here: https://pchutney.com/strip/348