Select Privacy and Security in the left side menu.
Select Site Settings.
Select Pop-ups and redirects.
Select Add next to Allowed to send pop-ups and use redirects.
Input the specific page URL and select Add.
From the Firefox menu, select Settings.
Select Privacy & Security from the left-side menu.
Under Permissions, select Exceptions next to Block pop-up windows.
Input the specific page URL.
Select Save Changes.
Open the Settings and more menu at the top right of the window.
Select Settings.
Select Cookies and site permissions.
Select Pop-ups and redirects.
Next to Allow, select Add.
Enter the specific page URL.
Click Add.
From the Safari menu, select Preferences.
Select Pop-up Windows from the left side menu.
From the when visiting other websites drop-down menu, select Allow to allow all pop-ups from all websites.
Alternatively, you can select Block and Notify to receive a notification whenever a pop-up has been blocked. From there, you'll have the option to allow exceptions as needed.