Use your application's credentials and the user's credentials to retrieve an access token by sending a HTTP POST message to https://app1pub.smappee.net/dev/v1/oauth2/token
...
If the server side validation of the passed credentials went well, you will receive a HTTP OK containing the token information (see below). This token has to be passed with each successive API call. The token has an expiry period of 10 hours (36000 seconds). After the token has expired, you can use the Refresh token to retrieve a new access token.
...