It's possible to make use of your own URL shortener by connecting your existing Bit.ly account.
To do this, click on your user icon top right in the navigation bar: ..and choose 'Personal Settings'.
Then click on 'Advanced'. You should see the option to add your Generic Access Token:
Fill out the Generic Access Token of your existing bit.ly account and click 'Save'.
For every future article, the platform will generate custom short URLs for articles of that account.