virtualmin/webmin amd mime types

hello all - i have started "experimenting" with opus-codec files.

i notice when i just go to a link directly for an opus file on an example page, it just plays, as expected (at least in firefox it does)

however, when i do the same thing on my server, the browser wants to download it instead.

under webmin-->system-->mime, i tried to manually enter:

audio/ogg

(please see attached)

but this did not work.

i did run a web-sniffer, and my mime-type is still coming through as "text/plain; charset=UTF-8" not "audio/ogg"

can anybody shed some light on what this newbie is doing wrong?

also, should this value end up going into the httpd.conf file?

thank you all for your help!