The service of goo.gl will be not available for the anonymous and new users from the 13 April 2018 but existing user can access these service for another 1 year. It will completely shut down on March 30th, 2019.
if you are currently using the URL Shortener APIs to manage all your goo.gl short links, then you can continue using till the time it completely discontinued on March 30, 2019
For the more detials: Transitioning Google URL Shortener to Firebase Dynamic Links
If you like FreeWebMentor and you would like to contribute, you can write an article and mail your article to [email protected] Your article will appear on the FreeWebMentor main page and help other developers.