It’s not enough to put the dremio JDBC driver jar in the plugins folder. Some Clojure code also need to be written and included in Metabase.
Maybe my post in this thread helps explain: DB2 Support
A while ago I actually spent a few hours trying to write a dremio.clj file. I based my attempt on redshift.clj and got it to fetch some Dremio metadata but had it failing on other parts…
If I should decide to take up trying again I would base it on the Drill attempt as mentioned in the https://github.com/metabase/metabase/issues/2157#issuecomment-383636751