[Spring Security]Grant authority when creating an account

[Jan Kaczmarek]

Hello,
Is there a way for me to grant authority while creating a specific account? Now, depending on whether I have true / false (in my AppUser model is a class field boolean isProfessor;) or admin, the user gets the appropriate permissions in my implementation of UserDetailsService. It does not seem to me to be a correct and elegant solution. Can I add in the AppUser model something like "authoritiy" field and when creating set "who it will be"? STUDENT or PROFESSOR
Now it looks like:

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        String admin = "admin";
        AppUser appUser = appUserRepository.findByUsername(username);
        Collection<GrantedAuthority> authorities = new ArrayList<>();
        if (appUser.getUsername().equalsIgnoreCase(admin)) {
            authorities.add(new SimpleGrantedAuthority("ADMIN"));
            return new User(admin, admin, authorities);
        }

        if (appUser.isProfessor()) {
            authorities.add(new SimpleGrantedAuthority("PROFESSOR"));
            return new User(appUser.getUsername(), appUser.getPassword(), authorities);
        }
        if (!appUser.isProfessor()) {
            authorities.add(new SimpleGrantedAuthority("STUDENT"));
            return new User(appUser.getUsername(), appUser.getPassword(), authorities);
        }
        throw new UsernameNotFoundException(username);
    }

Thank you for any advice!