Can a passkey be hacked and exported?

Simple question, but hard to find an answer, if a hacker can have access to my computer and also has my 1password password, I know he can export all my passwords and other data, but how about passkeys? 

1Password says the we can't export passkeys and import into other password managers, but could a hacker do it?

I know that in this situation the hacker could use my computer to change or disble my passkeys, but another type of attack would be clone my passkeys and get silent access to my accounts. This is totally different than change/disable as I would notice. 

Thanks