Put some pigeon poppers on the top:
​
https://www.amazon.com/One-Sight-Stainless-Deterrent-Repellent/dp/B07ZHY6HMY/ref=sr\_1\_4?crid=UFZSJHERCU5Y&keywords=pigeon+spikes&qid=1640811071&s=lawn-garden&sprefix=pigeon+%2Clawngarden%2C440&sr=1-4
https://www.amazon.com/One-Sight-Stainless-Deterrent-Repellent/dp/B07ZHY6HMY