How can I add private key to the distribution certificate?

Hi! the error say
then it tells me that I have to put my keychain
the question is how?
my mac os is no longer accessible because it burned

What should I do to create another account so that they give me another certificate?
It is impossible it always tells me the same thing even if I give it in the xcode to generate the profiles and everything always tells me that there is no key?

thanks