RB2011iL-IN - how to reset to default settings

Hello. I’m newbe with RB2011iL-IN.
Sorry about this dumb qustion (I tried to investigate the forum before creating this topic).
I can’t log into the admin panel. Thus I decided to reset the configuration of my router.
I tried two ways: first I tried to hold the reset button for 15 sec after swithing on the device.
Second, like in PC motherboards I tried to put screwdriver into the jumper hole until the process of swithing on.

I have Internet from provider, everyhing is fine. I can log into the page 192.168.88.1
After that, I see the admin panel:

login: admin
password: (empty box)

No one efforts to log into admin panel has been successful (“incorrect data”).
Please, help me in this situatin. Thanks.

Was the IP address different before you reset it? Was it something other than 192.168.88.1?

My suggestion would be to get a console cable for it (same as Cisco’s).