According to the documentation the signing key has to be added as follows:
root@mx-precision-5570:/home/reinout# wget -q -O - https://packages.mendix.com/mendix-debian-archive-key.asc | apt-key add -
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
As you can see it complains that apt-key method is deprecated. Expectation is that the documentation follows the officially supported method.
According to the documentation the signing key has to be added as follows:
As you can see it complains that apt-key method is deprecated. Expectation is that the documentation follows the officially supported method.