All metadata for ePub development is stored and should always be referenced from Firebrand.
To access metadata from Firebrand without pulling it manually the following must be installed in your user root directory, example:
bash1Macintosh HD > Users > codingChewie
Under the user directory create a folder named Firebrand_Digital_Product_Lookup. There can be no other naming conventions for this directory due to other apps and scripts that reference the files when ran and an easy way to create this is with the terminal command:
bash1cd && mkdir Firebrand_Digital_Product_Lookup \2&& cd Firebrand_Digital_Product_Lookup \3&& curl -O https://github.com/epubknowledge/scripts/blob/main/opf/firebrand-installer/Firebrand_ePub_DC_Metadata_OPF.xsl \4-O https://github.com/epubknowledge/scripts/blob/main/opf/firebrand-installer/Input.xml \5&& open Firebrand_Digital_Product_Lookup
The above code assumes Bash's root is your User directory. Once ran it will create the directory and download the two needed files:
then open a new window Firebrand_Digital_Product_Lookup showing the above two files.
A secondary alternative is to download the app firebrand-installer.app and it will generate and place everything for you.