How can i make my telkom wifi vissible for other devices

Ask your ISP, this, call them on the phone
ask your service provider.
not told you what country or city you live
we do not have Telkom in USA so answers hard to do.
GENERIC ANSWER, 1000's of miles from you..

The system you have there was not told by you , all parts of it.,
like Service provider, not told. nor city.
MODEM to them. installed by them, not told, DSL,. CABLE or?
nor your WIFI router, they put it there then call only them.

visible means the router broadcasts the SSID
if that is turned off , then it can not be seen.
see this?
see them all here in the HOOD
a cell phone or PC app can do this magic, wifi radar
to see all SSID in the hood, not too far away.

https://www.pcdied.com/wifi-sux/docs-photos/inSSIDer%202.1.6.1394.png

if you call he service provider they will tell you your
wifi credentials if you ask them.
on my system PIN and WPS is disabled by me it is dangerous.for sure in any crowded hood.(dense)
good luck !!