In order to use a Twitter feed on your website, you need to tell Twitter that you are the owner of account used. To do this, you need to create a Twitter Application.
Here’s the steps:
Creating a Twitter Application
The Twitter Widget will never ask for your password, as it gets all your required data from the Open Authentication keys and secrets you will get by creating your application at Twitter. It also means that if you change your twitter password, you won’t need to update any of the details of your Widget.
Go to https://apps.twitter.com/ and sign in.
Click “Create New App.”
Enter a unique Name (anything you want), a Description (again this is just for you), and your site’s URL. You can leave the Callback URL empty as it is not used for this implementation.
Click the “Keys and Access Tokens” tab.
Click the button “Create my access tokens“.
Now you should see all the keys that are required.
Good. Now go to your WordPress Dashboard and go to the Settings > Twitter Feed Auth.
You can just copy the required information into the exact corresponding inputs fields of the Settings options: