Twitter hashtag feed not working

I created a twitter feed using twitter widget and its working fine on my website but I am not sure how to display tweets from a specific hashtag. I tried the twitter backward compatibility widget and types the hashtag under search but its not displaying anything.

I have also created a twiiter application and registered it but I don't know how to display tweets from a hashtag using that. Please provide steps I need to take to do this.

Thanks,

also, I noticed that when I access the page after a few hours the feed stops displaying feeds. I then registered a new feed and displayed that. This happened to me twice, I was wondering if I am doing something wrong or is there something else. Does the consumer key or token expire? I am confused.