When you highlight part of a document, select Copy with Reference. The highlighted part will be copied along with the citation in the format you pick (Standard (Bluebook) , ALWD or state specific).
Not all states are currently supported. Ohio citation format available.
Select Briefs or Law Review Format: the default is Bluebook for legal briefs; if you want to change to Bluebook for Law Review form, click on Preferences in the bottom left, then click on the Citation tab, and select Law Review as citation style.