Errors

valid_signature

gpg: Signature made Sat 18 May 2024 01:53:44 AM 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! <==