Follow Debian recommendations
As described here: https://wiki.debian.org/DebianRepository/UseThirdParty#OpenPGP_Key_distribution
The key MUST be downloaded over a secure mechanism like HTTPS to a location only writable by root, which SHOULD be /usr/share/keyrings. The key MUST NOT be placed in /etc/apt/trusted.gpg.d or loaded by apt-key add.
Also, the /
at the end of the url is not needed.
Edited by Issam E. Maghni