AUR is unsupported whether you are using Manjaro or Arch.
The installer source does not exist anymore - that is - jugding from the result of the download url.
It is a well known issue with expired domain names - some picks it up and leeches on the domains previous history.
The package was flagged out-of-date (2022-02-07), I am guessing the invalid source link.
If it is indeed a valid application you will have to figure out where you can obtain the source - from there you can build the package manually - but the forum does not deal with those un-maintained packages - you will have to figure that out on your own.
https://wiki.archlinux.org/title/Arch_User_Repository
The upstream URL is https://zeppelin.apache.org/
Be sure to note the Python version supported is Python 3.9 (Zeppelin) in contrast to Manjaro Python 3.12.x.