Made a connection like written on github. That doesn't work, and throws: exit status 1

Figured out this throws when I try to ping connection. 

Tried to make connection like was displayed on official mongodb website: https://www.mongodb.com/golang Italic

But there they do not make ping, and making magic with connection string I tried to compile my Go project, but when I wrote the API endpoints that retrieves the data from DB, I get 500 HTTP ERROR on every route, that was integrated with database.

Also, it doesn't connect to database without +srv within mongo and :// in connection string. I would like to get the right format for connection string to connect to MongoDB Atlas.