q2-brocc error about nt database import

Hi,Kyle.I have also met a problem with brocc .

I have installed q2-brocc.I run the'blastn -query query.fasta -db mitogenomes -outfmt 7' code and I can get the hit result(mitogenomes is a customed nt database).

Then I run 'qiime brocc classify-brocc --i-query query.qza --o-classification query_brocc.qza' code and it returned 'BLAST Database error: No alias or index file found for nucleotide database [nt] in search path [/data1/WJJ02/YLB03/Software/Qiime2::]
'
Then I run 'qiime brocc classify-brocc --i-query query.qza --o-classification query_brocc.qza --p-blastdb mitogenomes' and it returned 'Did not detect a local copy of the NCBI taxonomy.Using NCBI EUtils to get taxonomic info instead.IndexError: list index out of range
'
and my nt folder including 'nhr','nin','nsq' files and so on.

Could you please help me?