Is there a script or add-on for google sheets that counts the number of used cells?

I am getting the error of reaching the 5 million cell limit in Google Sheets

I’m wondering if there’s a script or add-on to count the used cells in the sheets/workbook

I found this add-on called sheetgo, but can’t see the count option in the menu, wonder if there’s an alternative.
https://blog.sheetgo.com/spreadsheets-tips/google-sheets-5-million-cells-limit/