About SSL connection

Hi,
i was trying to enable SSL on postgresql 10 and 11 Servers after searching
on postregsql documentation i found this :

ALTER SYSTEM SET *configuration_parameter* { TO | = } { *value* |
'*value*' | DEFAULT }

on https://www.postgresql.org/docs/10/sql-altersystem.html
i used

ALTER SYSTEM SET SSL = ON , querry executed successfully

after that i entred this Select * from pg_settings , i saw that ssl
value is off,

after stoping the service of postgresql it wont start again

i tried this on both servers 11 and 10 the same problem (the server
wont start again)

I'm using widonws 7 x64.

my question is how to enbale SSL ?

ps : i created all require cert files.

sorry for my bad english.