Hi @Tepp 

this is not possible to override the default “New” button (which is platform-generated) to open a modal window out-of-the-box. However, you can implement custom solutions.

You can simulate a custom UI Action (e.g., button or link) that opens the new record form in a new browser window or tab.

var url = "/your_table.do?sys_id=-1";
window.open(url, "_blank", "width=800,height=600");

You could use GlideModal or custom modals with iFrames, but this is generally unsupported and discouraged in the classic UI.


Please Mark this Helpful and Accepted Solution. If this Helps you to understand. This will help both the community and me..
- Keep Learning ‌‌
Thanks & Regards 
Deepak Sharma