You need to tidy up your code.
Had to clean a lot just to try it out.
Code:
Sub TestFSO()
Dim db As DAO.Database, rs As DAO.Recordset, fs As Object, a As Object
Set db = CurrentDb()
Set rs = db.OpenRecordset("Transactions", dbOpenDynaset)
Dim Path, EmailType, TextLine As String
'EmailType = DLookup("[Lvl2 Group Name] &[,]", "t_email_list")
Set fs = CreateObject("Scripting.FileSystemObject")
Path = "F:\Temp\TestFSO.txt"
Set a = fs.CreateTextFile(Path, True)
rs.MoveLast
rs.MoveFirst
Do While Not rs.EOF
a.WriteLine rs.Fields("Description")
'.a.WriteLine ("This is a test.") '... This works, but the above line doesn't
rs.MoveNext
Loop
rs.Close
Set rs = Nothing
Set fs = Nothing
End Sub
Do not make stuff up, go look for the syntax.
https://wellsr.com/vba/2018/excel/vb...file-with-fso/
Dave's option will works as well providing you get the rest of the code correct.