Fullscreen cover at starting page on wordpress 5.6 [ add Warning message]

Hello all,

I would like to cover a patch (Fullscreen) on starting page in WordPress.
Unfortunately, I can’t find the right way to do it.

Here what I’ve tried so far:

  1. Get an API-key and install the plugin for cable.
  2. Select a patch with display option (on screenshot).
    ther result was no error, It just doesn’t appear.

There is an Advanced integration.
for example:
Use this shortcode anywhere in the Wordpress-Editor to display your patch in-place:
[cables_patch id=‘5ff737ca3d4f797fe9de7f4d’]
However, I can’t figured it out, how and where can I past to above the line ?( sorry for the newbie question)

It would be great if someone share a step by step instruction? or guide line/ link for tutorial?
Any help is appreciated!!
Thank you.

I solved this issue!!

would be nice if you could share how you solved this. so people can find a solution for maybe similar problems in the future. thanks!

I was confused that I solved the issue but actually not.
The warning still appear and the patch is not appear with my theme.
But if someone use default theme on wordpress with short code, It’s definitely works.(but no customlize dimension)
Just copy and past the short code
in text wordpress.