How to trigger a failed Timer modelled as "intermediateCatchEvent" manually

ENV: camunda 7.7, OpenJDK1.8_131, MySQL 5.7.20, Springboot 1.5.8.RELEASE

We have a Timer modelled as “intermediateCatchEvent”. After this Timer is a SystemTask. An earlier version of this SystemTask didn’t work properly and threw exception. This caused this process to be rolled back to that Timer. The SystemTask was now fixed, but that failed ProcessInstance still there. We’d like to trigger this Timer from outside, say e.g. using Camunda REST API, to given this ProcInst another chance to finish. We tried: modification/execute, process-definition/id/restart and execution/id/signal. None has worked. We would be very grateful for an advice. Thanks!

Never mind. job/{id}/execute did the trick.