Running biobakery wmgx with custom databases

I have installed the biobakery workflow and want to run the wmgx pipeline on some metagenomic samples. I have the standard chocophlan, uniref90 diamond and utility mapping DBs and can get everything to work just fine with those. However, the samples I have come from the oral cavity, and I would like to use HOMD genomes (HOMD :: Human Oral Microbiome Database) for increased accuracy.

Could someone guide me through how to create a custom db from the downloaded HOMD genomes fasta file, or link me to the appropriate resources?

Thank you so much in advance!