1. Login to your WordPress Admin section, select the Add New screen under Plugins and search for Mailcastr. or get it from this link -https://wordpress.org/plugins/mailcastr-bot/
  2. Select the Mailcastr WordPress plugin and click Install.
  3. After installation, find the Plugin and click the Activate link.
  4. You'll then want to paste the widget API key and save changes as per below-
  5.  You can find the key in the corresponding bot's settings page in your Mailcastr dashboard
  6. Click on the publish button to see the bot on your site!