How to add Decora WiFi switches in SmartThings

Hi. First post for me. Living in our third house now, and working on my third generation of smart home. I don’t remember what I used in the first house. Second house was all HAI automation panel, sensors, and switches. Now we’ve moved and bought a house, and I’m adding Leviton Decora WiFi switches on many lighting circuits (“simple” circuits, 3-way, 4-way, and 5-way).

I’ve added all of the switches in MyLeviton app and account, but haven’t been able to get any of them recognized in SmartThings. What’s the trick to doing this? I’m running SmartThings version 1.6.36.

Thanks in advance, and let me know what additional information is needed. I’m going to start a second thread on a different topic.