This sentence means "We often go for a walk." but unless one uses the exact word order Duo wants your answer is not acceptable. I would rather be learning German than trying to memorize the word order Duo prefers. Frustrating.
so many ways to say "walk". Sometimes we use "gehen" which is really "to go", then we have "laufen" which is "to run", also "wandern" which is "to hike". Now we have "spazieren" which is "to stroll". I never know which one to pick.