There seems to be an issue with some browsers not working making payments using PayPal. Try another browser.
I had an issue paying for an eBay purchase using FireFox browser recently. It would not go to PayPal, just kept spinning when going to the PayPal site. I switched to Microsoft Edge browser and no issues at all.
I just bought another item today and FireFox browser worked fine. But FireFox upgraded to the latest version yesterday so perhaps that fixed the issue I was having.
I tried another browser because I read in these forums in the past few weeks members having similar issues. With Google Chrome browser.