Paypal Payments Plugin: won’t connect

According to Woocommerce, the new Plugin “Woocommerce Paypal Payments” is supposed to replace those that have gone before. This is now recommended instead of PayPal Standard etc.

I have a PayPal business account, but I can’t get the two to connect when I press the button on the settings. It goes through to log in to PayPal, which I do, but ends up with “sorry, something has gone wrong” error message.

I have looked to manually set up, but it’s asking for a Client ID, which appears to be something on a developer account, not a business account. It also wants a Merchant ID, which I found. I didn’t get as far as searching for the Live Secret Key.

How do I connect? There is literally nothing on the internet about this. Everyone just says use PayPal Standard. I’ve been able to set up PayPal Standard, by the way, and receive a payment. I figured, as this is a new shop, I should try to new plugin to avoid me having to re-do it in the future. However, I’m completely stuck.