ِSafari doesn’t open the pop-up window because, Safari for macOS has no per-website control over blocking pop-up windows. Pop-ups are either blocked, or they are not. To allow pop-ups:
Step 1: From the Safari menu, choose Preferences… and click the Security tab.
Step 2: Ensure the Block pop-up windows option is not checked. Unchecking this option will allow pop-ups.
Step 3: To block pop-ups once again, check the Block pop-up windows checkbox.
Note: If you are concerned about allowing pop-ups globally for all websites that you browse, consider using another web browser that allows website exceptions such as Chrome or Firefox.