Don't PASTE images, use the "add image" button in Itch when creating a post.
As far as I understand, in godot 4.3 you can disable multithreading and disable array buffering when exporting to HTML, that would be the simplest solution.
Can confirm from firsthand experience, Godot 4.2 projects can be opened in 4.3 and work without SharedArrayBuffer (mine works when I open it in Firefox).
