[arch-general] Cannot install bacula-client error unknown public key

Hi, I try install bacula-client in my archlinux but I get this error: -> Found bacula-fd.service ==> Validating source files with sha256sums... bacula-7.0.5.tar.gz ... Passed bacula-7.0.5.tar.gz.sig ... Skipped bacula-fd.service ... Passed ==> Verifying source file signatures with gpg... bacula-7.0.5.tar.gz ... FAILED (unknown public key 9E98BF3210A792AD) ==> ERROR: One or more PGP signatures could not be verified! ==> ERROR: Makepkg was unable to build bacula-client. ==> Restart building bacula-client ? [y/N] How can resolve it? Thanks in advanced.