If you're wanting to create a self service policy object that users can run to execute sudo jamf policy and sudo jamf recon, these are the steps you'll want to take. I haven't seen a clear and concise post on this so I wanted to create one.
When creating the Policy, in the General payload, you'll leave all triggers off because you want it to be triggered by Self Service. For the execution frequency, set it to be Ongoing. Then add the Maintenance Payload and hit Configure. This will automatically have the Update Inventory selected. The update inventory essentially does what a “sudo jamf recon” would. Then to also have it force a check-in, go to the Files and Processes payload and under Execute Command you can put in “jamf policy” without the quotes. Lastly, make the policy available in Self Service. This will then ensure a check-in and update inventory will occur when a user selects that button.
