Newer releases for focal

Manfred Hampl suggests this article as an answer to your question:
FAQ #3037: “no rolling release”.

You are misunderstanding the meaning of "long term support". It does not mean "long term update"!

@m-hampl you're right. However, webservers which also need FTP will use the LTS release: the greatest part of users who use ProFTPd (I think) it's under LTS releases

Ubuntu 20.04 is supported for 5 years, not 10. It is EOL in April 2025

I read April 2030 from the wiki...
https://wiki.ubuntu.com/Releases

Anyway, why won't you update the focal package?

Some details for the different support dates:

see https://wiki.ubuntu.com/Releases

End of standard support for Ubuntu 20.04 LTS will be April 2025, but then there will be five additional years of "ESM" support - "Extended Security Maintenance is a paid option through Ubuntu Advantage to get extended support and security updates for select server packages."

proftpd-dfsg is a server package, but it is in the "universe" category. As far as I know only "main" is covered by ESM (everything subject to modifications and amendments).

"why won't you update the focal package?"
Did you read the FAQ?

Yes, I read it and it says:
There are exceptions to this rule, e.g. a limited list of packages like kernel, timezone information, Firefox, and in case that **severe weaknesses and/or bugs in a package justify an upgrade.**

ProFTPd has adrdress a lot of issues (major and minor) in 1.3.7

Ok, and then continue reading and follow the links for the process to be followed.

Ok, so I've submitted a bug in the ubuntu backports repo and I have uploaded a backport to this PPA (I think) using the backportpackage command.
Now do I only have to wait it gets approved?

I suspect that you misinterpreted the PPA upload step.
To which PPA did you upload the package?

I used this command: backportpackage -u ppa:ubuntu/proftpd-dfsg -s impish -d focal proftpd-dfsg
So I think to ubuntu/proftpd-dfsg

Such PPA does not exist.

So what is the right PPA?

There is no "right PPA". If you want to prepare everything for a backport, then you have to create a PPA of your own and prove that everything works in it.

What exactly do you want?
Do you want to help preparing that new version for everybody else or do you just need this version on your own system?

For the latter you could try manually downloading the packages for hirsute or impish and manually installing them on your system.