Im wondering how to create a countdown timer that waits for like a minute. But you cannot see the time left.
Assuming you're working with C# in Unity, check out Time.timeSinceLevelLoad. It's a read-only float that equals the time in seconds since the scene loaded.
Unity docs: https://docs.unity3d.com/ScriptReference/Time-timeSinceLevelLoad.html
A co-routine with a "Yield WaitforSeconds" is probably what some people are referring to
You can find a sample here https://docs.unity3d.com/ScriptReference/WaitForSeconds.html
Co-routines are pretty awesome for handling something when you need a specific period of time to lapse before doing the next thing :)
You can also use the update method and Time.deltaTime to check if a certain amount of time has passed https://docs.unity3d.com/ScriptReference/Time-deltaTime.html.
Both methods should do what you are looking for :)