Emacs e gpg

Hello as a object I've got a problem by Emacs and gpg, when I want to install new package (acutex).
Summary my situation

• Slackware version: 15 stable, fresh installation and updated. I use next mirror because it works fo fine to me http://mirror.datacenter.by/pub/slackwre64-15.0/ ;
• Emacs version: 27.2 which is on Slackware repository;

When I try to install new package by Emacs I obtain next error

Quote:

Failed to verify signature archive-contents.sig: No public key for 645357D2883A0966 created at 2024-07-15T23:05:01+0200 using EDDSA Command output: gpg: Signature made Mon 15 Jul 2024 11:05:01 PM CEST gpg: using EDDSA key 0327BE68D64D9A1A66859F15645357D2883A0966 gpg: Can't check signature: No public key

I try to searche solution without good goal, for example https://elpa.gnu.org/packages/gnu-el...ng-update.html . It's very hard to me to resolve it:banghead: