There isn’t anything just in the simple features in the SmartThings app.
It’s pretty easy to do it By Daisy Chaining with a virtual switch so that whenever that switch turns off relay turns on and vice versa, but that’s probably not the most popular way now.
Now there are several community created edge drivers that have all kinds of timer options in them. I think the following would probably best suit, but you can find additional ones on the quick browse list for virtual devices.
Alternatively, there is a third-party app with a much more powerful rules engine than the basic one in the SmartThings app which is also very popular. I’m not sure exactly how you would do this with that one, but you can look into it. They have their own community forum and also their Tech-support is usually very helpful. They have an annual license fee with the more sophisticated options, a free tier for the simple stuff, and a free trial if you want to check it out. You can find lots of threads in this forum from people using it, it’s very popular.