Oh wow, didn't know someone was hosting this manual, that's very helpful (wonder if tesla will issue a take down on it).Another link to a service manual showing an OBD connector on a Model 3 in the driver footwell. (this one says APAC only, but that may predate 2020)
Not sure how to remove the clips (they look like some sort of plastic rivet?)
I'll check out the cover on my 2022 M3 when I get a chance to see if it's got the connector.