public void onCheckboxClicked(View view) {
        CheckBox user = findViewById(R.id.checkBox);
    if (user.isChecked()) {
        has_vis = getSharedPreferences("hasVisited", 0);
        SharedPreferences.Editor editor = has_vis.edit();
        editor.putBoolean("hasVisited", true);
        editor.apply();
    } else {
        has_vis = getSharedPreferences("hasVisited", 0);
        SharedPreferences.Editor editor = has_vis.edit();
        editor.putBoolean("hasVisited", false);
        editor.apply();
    }
    }

sp = getSharedPreferences(REFRESH_TOKEN, MODE_PRIVATE);
        boolean hasVisited = sp.getBoolean("hasVisited", false);


        if (hasVisited) {
            Intent intent = new Intent(LoginActivity.this, SecondScreen.class);
            startActivity(intent);
        } else {
            try {
                submitBtn = findViewById(R.id.btn_submit);
                submitBtn.setBackground(getDrawable(R.drawable.button));
                submitBtn.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        sendPost();
                    }
                });

            } catch (Exception e) {
                Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
                    @Override
                    public void uncaughtException(Thread thread, Throwable ex) {
                        SendLogcatMail(thread, ex);
                    }
                });


            }
        }