GPG command to import Tor signing key does not work

When I try to import the Tor signing key using the command documented on the page https://support.torproject.org/tbb/how-to-verify-signature/

My terminal shows this error:

gpg --auto-key-locate nodefault,wkd --locate-keys torbrowser@torproject.org gpg: invalid auto-key-locate list gpg: Invalid option "--locate-keys"

OS: Linux Mint 18.3 GPG version: gpg (GnuPG) 1.4.20

Trac:
Username: issuefiler

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