To use SRA with SPS, you will need to be registered with Starling, and will need to ensure that your SPS appliance is joined to Starling. Below is a high level overview of the steps involved.
Go to cloud.oneidentity.com and register for Starling with your email.
Once registered, log into the Starling website. Under the Services section, click "View More Services"
Click the Trial button under the Safeguard Remote Access option to register it.
Next, log into SPS navigate to Basic Settings > Starling Integration.
Click Start Join. It should open a popup window with your Credential String and Token Endpoint, which you can copy and save.
The Starling Integration page should now show "Joined to Starling"
At the bottom of that page, there is a toggle switch for Remote Access, which you need to enable for it to be activated.