Open Chrome on your Chromebook
Click the three-dot menu in the top-right corner
Select Settings
Click Privacy and security
Click Site settings
Click Pop-ups and redirects
Select Sites can send pop-ups and use redirects
To allow a specific site, click Add under Allowed to send pop-ups and use redirects
Enter the website address
Click Add
Reload the website
If pop-ups are still blocked, click the pop-up blocked icon in the address bar and allow pop-ups for that site