This is the step by step FAQ.
On October 1, 2016, Amazon added the ability to turn on a " routine" from Alexa. If you want to use that method, see the official support article.
https://support.smartthings.com/hc/en-us/articles/210204906-Amazon-Alexa-SmartThings-Routines
Note that the official method will not allow you to use echo to run any routine that includes a lock or a Smart Home Monitor armed state change or another device class that Alexa does not know. The method described below in this FAQ will, but it does require that you create a virtual switch.
Although at present echo can only request that smartthings turn devices on, off or dim, by using a virtual switch, you can tell echo to turn that switch on or off, and then have all kinds of things happen in smartthings. For example, if you want to have echo tu…
The other topic people recommended was a troubleshooting thread set up to help one member who was having problems with his particular setup. It doesn’t use the regular method.
I would start with the FAQ first.
