To backup a database, use the BACKUP command.
Scripting a table is not a backup. It may be useful for other purposes, but a backup it ain't.
What it is the reason you don't want to include the N prefix? For an nvarchar column with data outside the code page, this could lead to data loss.
If the intention is to use the script on a platform that does not recognise the N prefix I am somewhat surprised, as the N is part of the ANSI standard, as far as I know.
In any case, SSMS does not any offer any option to leave out the N. You would have to employ your regular expression skills in a text editor to remove the N. The search pattern would be something like ([\(,]\s*)N')
and the replace pattern would be \1'
. The exact formation of the RE depends on the RE engine in editor. (And there is a faint possibility that you get some false positives and removes an N at the end of a character literal.)