IE automation with Checkboxes to fill form and submit

first post* new to VBA and coding, trying to learn as much as I can

Trying to automate internet explorer to do the following in this order:

• Loop through 7+ check boxes
  
  
  • if checkbox is true then link an adjacent cell's value
  • use that value to fill web form fields
  • select value from drop down(s) on web form
  • submit web form
  • close browser

  
  

I'm struggling to find documentation on how to link values when a checkbox = true

For i = 1 To 7+
If Sheet1.OLEObjects("CheckBox" & i).Object.Value = True Then
'...take string value
'...insert into form field  IE.Document.getElementsByName("MyString")(0).Value = ThisWorkbook.Sheets("sheet1").Range("a2")
'...select drop downs 
'...submit form 
'...close IE
Else
'...skip if checkbox isn't checked
End If

I have been unsuccessful at selecting drop down values.

IE.Document.getElementById("regionDrdn").Value = 2
IE.Document.getElementById("stageDrdn").Value = certification

If anyone has guidance, I would really appreciate it. Thanks