Translation:Every Independence Day they are doing Al Ha'esh in the park.
No one does al haesh in the park in English. The answer shouldn't even be allowed. It's also still not accepting "have a barbecue".
"Every Independence Day they have a BBQ in the park." They are doing is less grammatical. If its a habit once a year, the simple present forms, "they do/they have/they make/they host" are appropriate.