https://prnt.sc/tzpy8m
In the meta description box.. you need to enter..
%%ct_desc_wpdmcategory%%
Which means custom taxonomy description_then the name for the download manager category taxonomy.
Not a question, an answer this time, am posting it here, because it’s not an easy thing to find the answer to on the internet. Using this will mean when your download categories have descriptions (and they should).. Yoast will output those descriptions as a meta field in your web page headers. Search engines like Bing etc don’t like there not being meta descriptions for everything, so here you go.
You’re welcome..