Write a semi-formal email (100-150 words) to your supervisor, in which you want to apologise for not submitting your project. Mention: the purpose of the email the reason for the delay provide the solution to this situation (how can you fix things?)

Dear Mr Chochy I am writing to apologise sincerely for not submitting my project in the agreed deadline. The purpose of this email is to explain the situation and reassure you that I am taking immediate steps to resolve it. Unfortunately, I encountered unexpected technical issues with my data files, which significantly delayed my progress. […]