I tried adding the vungle sdk but after following all steps from the doc.coronalabs . i am still unable to use this featur . i get an error saying that the sdk was not successfully initialized can anyone help
 
 
 
 local ads = require(“ads)
 
function MyAds.initVungle()
    local function adListener( event )
        if ( event.type == “adStart”  ) then
            if(event.isError) then
                native.showAlert(VUNGLE, event.type … " " … event.response )
            else
                native.showAlert(VUNGLE, VUNGLE … "  ad starting”)
            end
        elseif event.type == “cachedAdAvailable” then 
            native.showAlert( VUNGLE,“showing chache ad”)
        elseif event.type == “adView” then 
            native.showAlert( VUNGLE,“ads time " … event.totalAdSeconds … " time watched” … event.secondsWatched )
        elseif event.type == “adEnd” then 
            if event.wasCallToActionClicked then
                native.showAlert( VUNGLE,“Ad not clicked” )
            else
                native.showAlert( VUNGLE,“ad clicked” )
            end
        end
    end 
    
    ads.init(VUNGLE,VUNGLE_APP_ID,adListener)
–    if  ads.getVersionString() ~= nil then
–        native.showAlert( VUNGLE, ads.getVersionString())
–    end
end
ads.show(“interstitial”)