If so, try to turn it off temporarily, connect the site again and see if you connected successfully

If it is a new installation of WooCommerce, it is very possible that the link structure does not support the rest API connection.

To enable this, simply do the following:

1. Log in to admin panel
2. Go to wordpress settings
3. Click on parmlinks settings 
4. change to any format other then simple.

Now try cunnecting again 🙂

Cloudflare should not be a problem. But, if you activated the blocking of countries or the “under attack” mode, it will prevent communication with the website

• Please unblock Germany and Britain.
• Please unavle “under attack” mode.

Then try again 🙂

If so, there may very well be a built-in block at the hosting level,
To resolve issue,

1. Login to your accunt: https://platform.cloudways.com/
2. Chose your application.
3. Go to aplication settings
4. Activate CORS Headers 
5. Wait 10 minutes
6. Try again 🙂

see more here:

https://support.cloudways.com/en/articles/5124964-how-to-enable-cors-headers-for-your-application