What exactly do you mean? What are you trying to do and what is happening?
If you mean you are using the Word plugin and you need to insert the bibliography at the end of the document, then place your cursor where you want the bibliography to go and click the Add/Edit Bibliography button in the Zotero tab in Word.
Note that Zotero’s support for Bluebook style is rudimentary. If you are doing legal citation, I recommend Jurism, a version of Zotero with much expanded legal support: https://juris-m.github.io
There is no such thing as a bluebook bibliography. The Bluebook only defines footnotes and Zotero's bluebook style only implements footnotes, so you wouldn't be able to add a bibliography for bluebook.
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If you mean you are using the Word plugin and you need to insert the bibliography at the end of the document, then place your cursor where you want the bibliography to go and click the Add/Edit Bibliography button in the Zotero tab in Word.
Note that Zotero’s support for Bluebook style is rudimentary. If you are doing legal citation, I recommend Jurism, a version of Zotero with much expanded legal support: https://juris-m.github.io