Drop down arrow

Hello,
i am using Enfold for quite a while for like 20 pages.
today i wanted to show a arrow in the menu, that indicates that there are some sub pages.

the mobile version has some of those arrows by default. It shows where i can klick on the sub pages.

but the normal menu on the desktop version does not have it. I also looked this up in this forum, but no css could do the work.

any fix for this?

best regards,
Igitt