Smallstep devices need to be trusted by the admin before the the Smallstep App will continue. This can be changed to auto-trust all new enrollments.
Our default team settings require all newly registered devices to be trusted first. You can opt to auto-trust devices in Settings under Team Settings.
Using the Smallstep Agent is another option. Smallstep App is very useful for proving (POC) as a trial but may or may not be ideal or necessary in large-scale production. We expect that in most cases, in production, you'd not use the Smallstep App and opt to push the agent to devices via an MDM.
How to Trust A Device to Resolve "Getting Things Ready" on devices using the Smallstep App.
As an admin, log into your Smallstep team, find the device, mark it as a "Trust device," and have the end user relaunch the Smallstep App
(Optional) Change the account team settings to self-enrollment