Errors

valid_signature

gpg: Signature made Fri 12 Apr 2024 10:17:10 PM JST
gpg:                using RSA key 6E1CD566E81F1EA49536F13B612A7DD8535C8ED0
gpg: requesting key 612A7DD8535C8ED0 from hkp server keyserver.ubuntu.com
gpg: Can't check signature: No public key
==> BAD/TAMPERED signature detected! <==