You can set Turnitin to accept any file type in Settings > Optional Settings.
However, please be aware that the different file types have limitations with Turnitin functionality.
For example, Excel files can be uploaded, but Turnitin only compares visible text. It does not look at formulas or hidden columns and will likely not display properly in Feedback Studio when you go to mark it. Excel files must be made using Microsoft Excel and not a third-party program that can save in the. XLSX format. Libre Office, Open Office, and others are not compatible with Turnitin and will not be accepted.