Introduction to REST API

Hi
I can’t understand, how can I make/find the ova file to setup virtual-services on the router?

Router(config-virt-serv)#activate                                  
% Virtual service csr_mgmt install has not completed, please activate the VM after install is completed
Router(config-virt-serv)#
^C
Router# virtual-service install name csr_mgmt package bootflash:?
bootflash:.dbpersist
bootflash:.installer
bootflash:.prst_sync
bootflash:.rollback_timer
bootflash:core
bootflash:csr1000v-mono-universalk9.16.08.01a.SPA.pkg
bootflash:csr1000v-rpboot.16.08.01a.SPA.pkg
bootflash:csrlxc-cfg.log
bootflash:cvac.log
bootflash:lost+found
bootflash:onep
bootflash:packages.conf
bootflash:pnp-tech-discovery-summary
bootflash:pnp-tech-time
bootflash:throughput_monitor_params
bootflash:tracelogs
bootflash:virtual-instance

Router#