Disable System Integrity Protection (SIP) / Recovery mode

Hi there,

I am running a MacBook Pro mid-2009 (Mac OS El Capitan 10.11.6) and have recently upgraded my internal hard drive to a SSD.

I have done a fresh install of the macOS.

I am trying to disable the SIP. For that, I need to restart my laptop into the recovery mode (Cmd + R) and access to the terminal.

While restarting and holding the CMD + R keys, the laptop is showing a stop sign.

I guess it's because a recovery drive is not available on my new SSD.

What is the best option for me to disable the SIP?

Thanks a lot for your help

Regards