You can't directly access DMs, but if you pay slack enough to export data for data compliance (I think it's the most expensive tier but it may be a lower one, b

You can't directly access DMs, but if you pay slack enough to export data for data compliance (I think it's the most expensive tier but it may be a lower one, but definitely not the free one), DMs are exported in that file, so you can indirectly get access to DMs that way.