Please do not do that.
You will find a iso here which includes most of the non-free firmware here:
https://cdimage.debian.org/images/unofficial/non-free/images-including-firmware/10.8.0+nonfree/amd64/iso-dvd/
Please take the time to read AND understand the information on that site.
I am sorry for giving inadequate advice. Please forgive me as I am new to Debian.
My idea was to install Debian, and then install non-free firmware.
This is the third question about "how to install Debian if I have nic that needs non-free firmware" I see in this list on this week.
So, what is the best practice to do so? Use an unofficial installer that contains non-free firmware?
If so, I believe this info is worth adding to the Debian installation guide somewhere in the wiki, so we can give a link to this wiki to newbies.
It seems that a lot of people face this problem trying to install Debian on their laptops.