How to ignore signatures when using apt update?

I'm using Kali for Windows (long story) and I cannot seem to install anything due to invalid signatures. The gpg tool isn't even installed, so I can't use gpg to validate signatures. I have tried the following, with no luck:

# sudo apt -o Acquire::AllowInsecureRepositories=true \
> -o Acquire::AllowDowngradeToInsecureRepositories=true \
> update
Get:1 http://kali.download/kali  kali-rolling InRelease [30.5 kB]
Err:1 http://kali.download/kali  kali-rolling InRelease
  The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository 
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://kali.download/kali  kali-rolling InRelease: The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository 
W: Failed to fetch http://http.kali.org/kali/dists/kali-rolling/InRelease   The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository 
W: Some index files failed to download. They have been ignored, or old ones used instead.

I've also tried the following, with an error as well:

# wget -q -O - https://archive.kali.org/archive-key.asc  | apt-key add
E: gnupg, gnupg2 and gnupg1 do not seem to be installed, but one of them is required for this operation