Please read the submission document and follow the guidelines/rules there, e.g. do not submit via myUnisa, ensure your site is available, and if not email... etc.
Some students submit a (dummy) URL, then wait for results, get code from a fellow student, then claim their site was deleted. Others submit, take their time to complete the assignment/portfolio, and then claim their site has been deleted.
Then I am accused of being unfair
The rules are clear - follow them. I cannot make a single exception because that would be unethical and unfair to students who bring their part. And 98% of students do so without any problem.