This could be done by manually inserting CSS into your exported project.
Step 1: Export project as HTML5
Step 2: Find style.css in your downloaded project folder
Step 3: Open the file in Notepad, find the line "body, html { }" (without " ") and inside of the brackets { } add this line:
-webkit-user-drag: none;
Step 4: Save file
The line should then look like this:
html, body {
-webkit-user-drag: none;
(other similar code can be seen inside)
}
If that doesn't work, try doing adding this line to the file style.css
* {
-webkit-user-drag: none;
}
This should work for both Chrome and Safari.