To hide the PayPal express checkout button on the checkout page, you can use PayRules: Hide Payment Methods app. First go to the “Add Rule” page and enable the toggle to Hide of the PayPal Express Checkout field like the below screenshot. This will hide the PayPal express button at the checkout page. To keep PayPal as a payment option, you can follow this short video tutorial as well https://www.youtube.com/watch?v=O27tWckVJ1k
I hope it works for you. Thanks.