Making a bot for Twitter is a multi-step process that consists of:
As of July 2018, you must apply for a Twitter developer account and be approved before you can create new apps on Twitter. You can start the process by going to this page with the account that will be used as your bot.
You will need to add a phone number to your account before you can proceed. If you are already using your phone number with a different Twitter account, you should be able to remove it by texting STOP to your country’s shortcode number, and add it to your new bot account.
A few people run into issues after reusing their phone number too many times, but you can also sign up for Google Voice, or any other service that lets you receive text messages (for example Skype Number doesn’t, so it won’t work).
Once your developer account is approved, you can go to the developer dashboard and click the Create an app button to create an app for your bot.
If you’re making a bot that will respond to DMs, you will need to provide the callback URL, which should be mentioned in the tutorial you’re following. Otherwise you can skip all fields that are not required.
Once you’re done here, go to the Keys and Tokens tab and under Access token & access token secret click Create to get your API keys. These will let you make API calls, or in other words, interact with the data on Twitter’s website.