The file should export with a .dae extension. Don’t double click on it to open it - that’s opening something like a Text Editor and showing you the XML contents.
Go to the File menu, then Import in SU8, choose the file type to import as I showed you, then find the file, probably in your Downloads folder, and select it.
Then click on the Import button in the bottom right of the file selection dialogue.
I’ve just tried it with a nearly empty SU Shop file.
Save your file in Shop, to the cloud.
Go to the menu then do the Export, and check all the boxes in the Export Options dialogue. Here they are before I checked the non-default boxes.
Click [Export] and you get this dialogue.
Wait till the conversion is finished. Then click on the underlined link
Import/Exports tab .
When the export is finished, you get a popup telling you so.
Then click on the download arrow to the right of your file
This is what I see when I go to my Downloads folder, and follow the steps above - open SU 8, File/Import, choose the Format DAE, select my Test DAE.dae file, then click Import.
Just follow the steps I’ve described. You’re doing something different at some point, if you aren’t getting the DAE export file with the extension .dae.