jwt 회원기능3(Filter) - Cannot invoke "Object.toString()" 에러

이전까지의 모든 실습은 잘 됐구요.
jwt마이페이지 버튼을 누르면 Cannot invoke "Object.toString()" because the return value of "io.jsonwebtoken.Claims.get(Object)" is null 에러가 뜨는데,
var arr = claim.get("authorities").toString().split(","); << 이 구문이 문제라고합니다.
그래서 sout로 출력을 해보면
System.out.println("*******"+claim+"*******");
System.out.println("*******"+ claim.get("authorities")+"*******");
*******{username=park, displayName=회원1, ahtorities=일반유저, iat=1741170251, exp=1741170261}*******
*******null*******
claim에 들어간 것들은 잘 나오는데, claim.get("authorities")가 null이 나옵니다.
어디서 어떻게 잘못된건지 감이 안잡힙니다ㅠ

----------SecurityConfing------------------------

public class SecurityConfig {

    @Bean
    PasswordEncoder passwordEncoder(){
        return new BCryptPasswordEncoder();
    }

    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {

        http.csrf((csrf) -> csrf.disable());

        http.sessionManagement((session) -> session
                .sessionCreationPolicy(SessionCreationPolicy.STATELESS));

        http.addFilterBefore(new JwtFilter(), ExceptionTranslationFilter.class);    //필터순서(JwtFilter)
        
        http.authorizeHttpRequests((auhorize) -> auhorize.requestMatchers("/**").permitAll()
        );

        http.logout(logout -> logout.logoutUrl("/logout")); //로그아웃

        return http.build();
    }

}


----------------------JwtFilter---------------------------

@Component
public class JwtFilter extends OncePerRequestFilter {

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        Cookie[] cookies = request.getCookies();

        if(cookies == null){
            filterChain.doFilter(request, response);    //다음필터 실행해주세용
            return;
        }
        var jwtCookie = "";
        for (int i = 0; i < cookies.length; i++){
            if (cookies[i].getName().equals("jwt")){
                jwtCookie = cookies[i].getValue();
            }
        }
        System.out.println(jwtCookie);

        Claims claim;
        try {
            claim = JwtUtil.extractToken(jwtCookie);
        }catch (Exception e){
            filterChain.doFilter(request, response);
            return;
        }

        System.out.println("*******"+claim+"*******");
        System.out.println("*******"+ claim.get("authorities")+"*******");
        var arr = claim.get("authorities").toString().split(",");
        var authorities = Arrays.stream(arr)
                .map(a -> new SimpleGrantedAuthority(a)).toList();

        var customUser = new CustomUser(claim.get("username").toString(), "none", authorities);
        customUser.displayName = claim.get("displayName").toString();

        var authToken = new UsernamePasswordAuthenticationToken(
                customUser, "", authorities
        );
        authToken.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
        SecurityContextHolder.getContext().setAuthentication(authToken);

        filterChain.doFilter(request, response);
    }
}

----------------MemberController-----------------------
@GetMapping("/my-page/jwt")
@ResponseBody
String mypageJWT(Authentication auth){
    var user = (CustomUser) auth.getPrincipal();
    System.out.println(user);
    System.out.println(user.displayName);
    System.out.println(user.getAuthorities());
    
    return "마이페이지 데이터";
}