@Rana95
Just click the transaction → Go to Menu → Rename → Put the new name you want and save. Kindly check the below link for reference:
https://erpnext.com/docs/user/manual/en/using-erpnext/articles/renaming-documents
Hope this helps!
Regards,
Reema
@Rana95
Check whether you have the user permission for renaming. If not then you will have to assign the role where you can rename.
Regards,
Reema