Device: Roku Stick
I recently noticed that the Roku software for Spotify was back (it had been pulled recently while waiting on an upgrade - the old version wasnt very good). I was interested to see what the upgrades were. I currently use Spotify on my android phone, iPad, laptops, Google home, and desktop and really love the vast catalog and the ability to switch between devices quite seamlessly.
I recalled that logging into Spotify on the previous Roku version with Facebook id was a bear to figure out. Theres was a combo of using long id strings, Facebook device passwords etc.
I saw that the login menu on Spotify for Roku now has an option to log in with a PIN. This option brings up a typical Roku activation - It provides you with a short code and a URL. Enter the URL in your phone or PC browser, followed by the presented PIN code. Your browser will prompt you to log into Spotify, and includes the log in via Facebook. Sign in and your Roku automatically is registered and logged and ready to go.
I also noticed that the Roku software now supports Spotify Connect. If you select your Roku via Spotify Connect from your phone or PC, it will log you into your account automatically, and that login will persist until you explicitly log out.
I am creating this post because I contacted Spotify support to assist me with trying to log in (before I tried the log in with PIN option) and they were utterly uninformed and useless on their on own Roku software. Hopefully finding this post will save others the painful 1.5 hours plus I had to deal with support. In the end, I discovered this on my own, while support was ignoring my messages.
Also note that the latest version (late 2018/early 2019) seems to log in differently than the previous, some some of the older posts on this topic are out of date.