https://www.juniper.net/documentation/us/en/hardware/ssr130/ssr130.pdf page 11 callout 7 indicates the reset button exists as seen on the physical appliance, but fails to indicate how long to press it for factory reset. It does not appear to work and has been complained about by multiple customers, some of whom have stated they cannot use USB in the data centers due to USB security policies/restrictions which is the only alternative.

factory reset pin hole doesn't work.

According to PLM there are no plans to add support for this functionality. A doc bug has been opened to update the public documentation to make this more clear.