Why is renaming Sales Invoice disabled?

In earlier versions, renaming Sales Invoice was allowed.

Seems its now disabled in v13.

Just wanted to know why it was disabled. I am using ERPNext with API integration, it is breaking my existing code.

Open your sale invoice → Click on your client name on top left of your sidebar a popup window will open

Hope this will solve your problem

That changes the title of the invoice. I want to change the name of the invoice itself.

as per this, Sales invoice is not allowed to be renamed

https://docs.erpnext.com/docs/v13/user/manual/en/using-erpnext/articles/renaming-documents

You can try custom translate as an alternative
https://docs.erpnext.com/docs/v13/user/manual/en/setting-up/print/custom-translations

If you can give an example I can help you more