Prevent formulas from recalculating on cell value deletion

[gumberino]

I am working on a project for work that involves HTTP requests. After struggling through getting that to work, my next problem is trying to prevent the VBA function from recalculating when one of the argument cells is cleared. Below is my attempt at a solution thus far:

Function HTTPGet(ISO As String, HE As Single, Node As String, Bid As Single, MW As Single)
    Dim sCmd As String
    Dim sResult As String
    Dim lExitCode As Long
    Dim Counter As Integer
    Dim MyArray() As String
    If IsEmpty(HE) = True Or IsEmpty(Node) = True Or IsEmpty(Bid) = True Or IsEmpty(MW) = True Then
        Exit Function
    End If
    sCmd = "curl --get http://localhost:8000/" & ISO & "/" & HE & "/" & Node & "/" & Bid & "/" & MW
    sResult = execShell(sCmd, lExitCode)
    
    
    
    HTTPGet = sResult
    
End Function

My attempt at bypassing this was the implementation of the IF statement after the variable types are all declared.

The problem I am having as stated, is that when one of the cells is cleared, it recalculates the function. Often times, I will need to clear 500 rows and apart from taking a long time, it is unnecessary HTTP GET requests to the server, which upon implementation, will no longer be on localhost.

Any help here is appreciated.