It depends on the monitor. If it already has Thunderbolt, you can only connect the corresponding Thunderbolt 3 cable to your Mac. For 5K, you need Displayport 1.4, which your Mac also supports but only a few docks come with. Therefore, I would rather recommend an adapter like this one: Club 3D Adapter USB Type C - DisplayPort 1.4 (DP, 22cm)