Example:
/lp group superadmin meta 100 addperfix "&4[&5Super&4Admin&5]"
When i add the quotations it still doesn't add a space

Perfect it work, thanks for help !

Well, your command is wrong.

It should be something like:

/lp group superadmin meta addprefix 100 "&4[&5Super&4 Admin&5]"

And then it works (for me at least)

Thanks lucko

Thanks @lucko