Run-time error '1004' ?

HI there on the code below I am getting run-time error 1004 whenever it reaches
Range("A3").Select

Please help

Sub UpdateBtn_Click()
 
    Sheets("Data").Select
    
    Dim NewMGRate As Double
    NewMGRate = InputBox("Enter today's MG Rate")
    Range("A3").Select
    Selection.End(xlToRight).Select
    ActiveCell.Offset(0, 1).Value = NewMGRate   
    
End Sub