question on streaming replication

Hi,

I have postgres edb 9.6 version, i have below query to solve it out.

i have configured streaming replication having master and slave node
on same server just to test it.

All worked fine but when i made slave service stop, and create some
test databases in master, after then i made slave service start, slave
didn't pick the changes.

The replication was on async state.

Then after doing some search on google i tried to make it sync state
but even making changes in postgresql.conf file I am neither getting
sync state nor getting any changes on slave server.

Please suggest the needful.

Regards,
Atul