Widget suddenly stops working

In one of my site, twitter widget on front end suddenly stopped working as as result it does not show any tweets on front end. It says message like…

Nothing to see here – yet
When they Tweet, their Tweets will show up here.

Earlier it was showing tweets but from last one week it stopped in between.

For more detail, please refer this screenshot https://prnt.sc/2AqpBt2XaYIy

Please let us know what is wrong with this plugin.

Thanks!