How can I add third party repostories like PPAs?

[luizmichelin-cmyk]

Please, does anyone know how (well, maybe the correct question would be "if is it possible") to install Howdy in Elementary 8? I'm going in circles with this one and while I was able to install it in Ubuntu 25, in Elementary 8 it falls in the same loop over and over...

Thanks in advance, folks!

[danirabbit]

elementary OS doesn't ship with software-properties-common which contains the add-apt-repository command. This for a few of reasons:

• When you add a third-party software repository you are giving a third-party administrative permissions to modify your computer. This is a huge security risk that shouldn't be taken lightly.

• Third party repositories can contain patched packages other than the thing you intended to install that can overwrite your system packages and cause errors, degrade your security, etc.

• Usually third-party repositories like PPAs are made for Ubuntu, not for elementary OS. Sometimes this works out okay and you can install and use the software normally, but other times you will get software errors. It's much better to use a supported installation method like Flatpak if it is available.

If you understand and accept the security risk and still want to add the third party repository despite the fact that it may cause errors on your computer with either the installed software or other software, you can install software-properties-common to get the add-apt-repository command. This should be done with --no-install-recommends flag to avoid installing other Ubuntu-specific tools and configurations:

sudo apt install software-properties-common --no-install-recommends

[luizmichelin-cmyk]

Thanks, Danira.
Ultimately, I was trying to setup Howdy, but a prior instance requested by Howdy was precisely PPA (among other options - and, to be honest, among them all the one I was at least more familiar with was the one I tried to use). Well, I know for a fact that Deepin integrates Howdy and even though I know the risks implied with facial recognition (not being as safe as passwords), I'll suggest this as an enhancement for Elementary 9.
While I know that this may seem a bit exaggerated (in terms of convenience), the reason why I was trying to do it is that I was setting up a notebook for a person with accessibility needs. While the final user may adapt to type his password, it does require extra effort from him. I thought about the option to try helping the user but, in the end, I understand your point.
Appreciate the input (for real!).
Thanks!