CURL issue on website

I have a website that's been live for quite some time and it uses an API to gather data from another platform (which we have no control over). Recently we have a CURL issue where my website can not process past a certain stage and ultimately means the website does not work anymore as it's a button that needs to be pressed to go to the checkout phase.

We have checked our server logs and there are no details about the issue and also spoken with ur provider for the server and no issues so we're unsure as to how to fix this issue.