I'm following a list of stocks and become more interested in them if they close above a certain price level. I've searched online and even IB and cannot find a way to receive an alert if one of these stocks closes above this level. Does anyone know of such a service.

The key word is closing price. Many alerts will alert you if it gets above that level but not on a closing basis.

Maybe via this ressource: https://www.tradingview.com/how-it-works/

Type of alerts:
https://www.tradingview.com/stock-charts-support/index.php/Alerts

Have you tried the TOS alerts?