Step 1: On the site details page, click on the Review Security button under the SECURITY AND FIREWALL section.

Step 2: This will take you to the security page, Scroll down and click on the Show More button under the Traffic Requests section.

Step 3: The next page will show all traffic logs of your site. Click on the Filter logs option on the top left side of the page.

Step 4:  On the Filters window, click on the Status Drop-down, select the Blocked option, and click on Apply button. 

That's it, you can now see the IPs that are blocked from entering your website.

If you want to unblock any IPs on this list, Click on the Add to Whitelist Icon at the end of the row.