Use the snap services command (and the stop/start/restart ones)
$ snap services --help
Usage:
snap services [<service>...]
The services command lists information about the services specified, or about
the services in all currently installed snaps.
[services command arguments]
<service>: A service specification, which can be just a snap name (for all services in the snap), or <snap>.<app> for a single service.
$ snap start --help
Usage:
snap start [start-OPTIONS] <service>...
The start command starts, and optionally enables, the given services.
[start command options]
--no-wait Do not wait for the operation to finish but just print the change id.
--enable As well as starting the service now, arrange for it to be started on boot.
[start command arguments]
<service>: A service specification, which can be just a snap name (for all services in the snap), or <snap>.<app> for a single service.
$ snap stop --help
Usage:
snap stop [stop-OPTIONS] <service>...
The stop command stops, and optionally disables, the given services.
[stop command options]
--no-wait Do not wait for the operation to finish but just print the change id.
--disable As well as stopping the service now, arrange for it to no longer be started on boot.
[stop command arguments]
<service>: A service specification, which can be just a snap name (for all services in the snap), or <snap>.<app> for a single service.
(there is also snap restart as well as enable/disable on a snap level)