if its possible how can i add the "com.liferay.blogs.api" api into my application?

it is possible. If you have gradle, just add

compileOnly group:"com.liferay" name:"com.liferay.blogs.api" 

to your build.gradle.
Contrary to this thread's title, you should utilize OSGi @Reference annotations to get a reference to the services, not BlogLocalServiceUtil.