The Spotify extension for Albert launcher allows you to search tracks on Spotify and play them immediately or add them to the queue. It also allows you to choose the Spotify client, where to play the track.
The extension uses the Spotify Web API.
For the proper functionality of extension, Spotify premium is required.
Visit: https://developer.spotify.com/dashboard/applications and log in with your Spotify account.
Click on the button Create an app and fill the form. You can use for example name "Albert" and description "Spotify extension for Albert launcher".
Once you click on Create, your new application window will appear. You can copy your Client ID and show Client Secret. Both are 32-character strings.
Click on Edit settings and add new Redirect URI. It doesn't
have to exist. In this example, I will use: https://nonexistent-uri.net/
Open your browser and visit: https://accounts.spotify.com/cs/authorize?response_type=code&client_id=[[client_id]]&scope=user-modify-playback-state%20user-read-playback-state&redirect_uri=https://nonexistent-uri.net/
You have to replace [[client_id]] with your actual Client ID.
When you press enter, you will get redirected to
https://nonexistent-uri.net/ with code in URL parameters.
Copy that string and note it down for the next usage.
I will use curl for this last step. Replace or export all variables and run this command:
curl -d client_id=$CLIENT_ID -d client_secret=$CLIENT_SECRET -d grant_type=authorization_code -d code=$CODE -d redirect_uri=https://nonexistent-uri.net/ https://accounts.spotify.com/api/token
Use your Client ID, Client Secret and code from the previous step.
It will send POST request and return JSON in the answer. You can finally get your Refresh Token.
The whole process is also similarly described here.