I would like to create a script activity in automation in order to update a Sales Object.

this is an exemple of script, how can i update this script to be accepted as A SSJS script in script activity?

    %%[
    
    var @rowCount
    set @rowCount = DataExtensionRowCount("ENT.My_DE")
    
    var @nmaratasDE, @rsRow, @i, @Contact_ID, @PhoneNumber
    SET @nmaratasDE = LookupRows("nmaratasDE")
    
    IF RowCount(@nmaratasDE) > 0 THEN
    FOR @i = 1 to RowCount(@nmaratasDE) DO
    SET @rsRow = Field(Row(@nmaratasDE, @i))
    SET @Contact_ID = Field(@rsRow, "ContactID")
    SET @PhoneNumber = Field(@rsRow, "MobileNumber")
    
    
    
    )
    
    
    set @result = UpdateSingleSalesforceObject('IN_Contact__c',@Contact_ID,Phone_Num_c,@PhoneNumber)
    
    
    ]%%