SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder

I was trying to run database example just to see how it works.
I created a desktop server app for my project, and I changed DATABASE_URL with mine and "service-account.json" with my json.

But I got this in the log:

> SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
> SLF4J: Defaulting to no-operation (NOP) logger implementation
> SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

I visited the link above **but** got no usable information why this is happening or where it is coming from...

25-04-2020: I checked connecting to database from my android client and it worked just fine. but not on the desktop server.