If the captcha window has the phrase "I'm not a computer" visible, click on that text. It's the next step that will display the images and tell you what to look for.
Otherwise, if you're using any type of blockers, try disabling them.
If Safari doesn‘t load a page or webpage items are missing
https://support.apple.com/en-us/HT204098
If you have not done this already, please try these standard troubleshooting steps.
1. Delete Caches and test.
Close all windows and quit all applications.
Hold "option" key down and click "Go" menu in the Finder menu bar.
Select "Library" from the dropdown.
Library > Caches > com.apple.Safari
Right click the com.apple.Safari file and select "Move To Trash.
Close windows and relaunch Safari.
2. Remove Cookies and test.
Safari > Preferences > Privacy > Cookies and other website data:
Click the “Manage Website Data” button.
It will take a while for cookies and caches to load.
Remove all cookies except ones from Apple, your internet service provider and banks.
3. Disable Extensions and test.
Safari > Preferences > Extensions
Select and disable all extensions and test.
Enable Extensions one by one and test.
To uninstall any extension, select it and click the “Uninstall” button.
How to make captcha code visible?
