Adding more clarity:
1) Here's the flow I'm going for:

2) Once I select the file in OneDrive; I am able to select the flow I want to use:

3) The job of the excel script is to just move the rows to the right (Note that the script works properly when applied to a sheet directly):
function main(workbook: ExcelScript.Workbook) {
// Get collection of worksheets in the workbook
let worksheets = workbook.getWorksheets();
// Loop through each worksheet and insert a column after column A
worksheets.forEach(sheet => {
let columnA = sheet.getRange("A1");
columnA.getEntireColumn().insert(ExcelScript.InsertShiftDirection.right);
});
}
4) Aim is to auto-save the sheet in OneDrive after the macro is applied. I'm nore if any flow step is required for it and thus, not added it
5) Once i select the OneDrive sheet and run the flow - I see it as succeeded in my "Run History":

However - I don't see the changes in my OneDrive sheet.
Am I missing something here?
PS - Hope this information can allow you to help me solve this. Happy to share more details!
Appreciate the help!