You can use this function it takes a data table as parameter and generates an excel file I don't know what your exact requirements are but this can be a good starting point and you can modify it further.
Imports System
Imports DocumentFormat.OpenXml
Imports DocumentFormat.OpenXml.Packaging
Imports DocumentFormat.OpenXml.Spreadsheet
Public Sub CreateExcelFileFromDataTable(dataTable As DataTable)
'Create a new Excel file
Dim filePath As String = "C:\example.xlsx"
'Create the SpreadsheetDocument object and set its type to Workbook
Using document As SpreadsheetDocument = SpreadsheetDocument.Create(filePath, SpreadsheetDocumentType.Workbook)
'Create the workbook
Dim workbookPart As WorkbookPart = document.AddWorkbookPart()
workbookPart.Workbook = New Workbook()
'Create the worksheet
Dim worksheetPart As WorksheetPart = workbookPart.AddNewPart(Of WorksheetPart)()
worksheetPart.Worksheet = New Worksheet()
'Create the sheet data
Dim sheetData As SheetData = worksheetPart.Worksheet.AppendChild(New SheetData())
'Create the header row
Dim headerRow As Row = New Row()
'Loop through each column in the DataTable and add it to the header row
For Each column As DataColumn In dataTable.Columns
headerRow.AppendChild(New Cell() With {.DataType = CellValues.String, .CellValue = New CellValue(column.ColumnName)})
Next
'Add the header row to the sheet data
sheetData.AppendChild(headerRow)
'Populate the data rows
For Each dataRow As DataRow In dataTable.Rows
Dim row As Row = New Row()
'Loop through each column in the DataTable and add the corresponding cell value to the current row
For Each column As DataColumn In dataTable.Columns
row.AppendChild(New Cell() With {.DataType = CellValues.String, .CellValue = New CellValue(dataRow(column.ColumnName).ToString())})
Next
'Add the row to the sheet data
sheetData.AppendChild(row)
Next
'Create the sheets
Dim sheets As Sheets = workbookPart.Workbook.AppendChild(New Sheets())
Dim sheet As Sheet = New Sheet() With {.Id = workbookPart.GetIdOfPart(worksheetPart), .SheetId = 1, .Name = "Sheet1"}
sheets.Append(sheet)
'Save changes
workbookPart.Workbook.Save()
End Using
End Sub
