I agree. I see iCloud messages only when I upgrade macos.
What device? What version of macOS.
When are you getting these messages? What is the exact wording of the message?
How to show us a screen image. Avoid personal identification.
(1) On the Mac you do:
command + shift + 3 Will take entire screen.
You hear a click
command + shift + 4 Lets you decide what to
take. Mouse pointer changes. Move mouse to upper left corner of
desire image. Hold down left mouse key where to start image. Drag
mouse to lower left of where you want to stop image. Release
mouse.
You will get a file starting with Screen Shot ... .png on the
desktop. example:
Screen Shot 2016-09-20 at 2.27.47 PM
(2) To upload the image in ASC, click on image icon.

You see the open file dialog.
Select the image.

<p>On Windows it's more complicated. Here is an
outline of one way. There are others. <br>
-- get a screen capture app.<br>
-- press prtsc key<br>
results go to copy
buffer<br>
get some photo app<br>
open photo app<br>
paste picture<br>
save picture as jpeg or png to
desktop.<br> <br>