I'll take care of this query for you about reports in QuickBooks Online (QBO), @Killian.
You can run a sales report with custom dates to get this information. Selecting a Weeks filter from the Display columns by drop-down menu will always start with a Sunday and end with a Saturday. Refer to the screenshot below for more reference:

You can find more information about customising reports in this article: Customise reports in QuickBooks Online.
Post a reply in the comments below if you have other questions about generating reports in QBO. I'll get back to you as soon as I can. Have a great day!