Can I print from my iPhone to an old ethernet-connected printer?

I said: ">it's interesting to read that the HP Smart app only supports wireless-capable printers; I would have thought it would only require network accessibility."

and you replied: "I am not sure that one must read it exactly like that. It does not necessarily have to mean that a wired network printer is out of the question. Also, a wired printer connected by Ethernet to a Wi-Fi router is indirectly wireless-capable..."

The reason I made this comment is that many of the instructions I read for using "AirPrint" say that the printer must be on the same WiFi network as the ios device. Eg, this apple support article - Print from iPhone - Apple Support says " Note: Your iPhone and the printer must be on the same Wi-Fi network. See the Apple Support article About AirPrint. " So at least from that article, it would suggest that the printer must be WiFi enabled.

I'm still pursuing the CUPS installation on my NAS ...

It's an HP Laserjet P1505N (N for networked, ie, ethernet port included).

It's on my home network with a static ip address (192.168.10.8). I can ping it from my laptop. iPhone is set for DHCP and is currently getting an ip address of 192.168.10.109 from my home router (DHCP range on my home network starts at .100).

Interestingly, I downloaded the 'Ping Lite' app to my phone, and I CANNOT ping anything on my home network - not even the default gateway (192.168.10.1). But I CAN ping google.com, microsoft.com, etc from the phone! I can also ping google.com by ip address. I've never bothered trying to ping anything from my iPhone before so I have no experience with this particular issue.

My Macbook Air is old and tired ... battery not good and I only use it for troubleshooting at this point. My point was simply that the printer is a reliable print target for any normal device such as a windows computer or a Mac computer. I realize now that you can play some games and use the Macbook as a way to enable access to the printer, but that's not my goal here. My goal is to load something onto the iPhone that will enable me to send a local print job to the printer over the home network (without any other devices being 'on').

It looks like the HP Smart app ought to be able to do that - I installed it on the iPhone and then had it search for devices on my network. It came back with the 'HP LaserJet P1505n', but now it's showing 'unavailable' for that device. I can still ping it from my laptop and still print to it from my laptop, so I don't know why HP Smart is no longer able to 'see' the printer. When I first set it up, it could 'see' it, but then wanted me to sign in / create account before it would complete the print operation.

@Jan - it's interesting to read that the HP Smart app only supports wireless-capable printers; I would have thought it would only require network accessibility. But that may explain the problem using HP Smart.

Regarding your comment:

"The latter could possibly be of interest if you wish to carry out experiments with a Raspberry Pi print server for AirPrint-like printing from an iPhone (or iPad, or modern Mac). Techguyuk mentioned a Raspberry Pi 3 in connection with a Kyocera laser printer (Can’t print with iPadOS17 - Apple Community). Tesserax reported about using a Raspberry Pi 3 Model B+ for an old HP LaserJet printer (Can I connect my laser printer to my netw… - Apple Community)."

I have been reading about a similar approach - using CUPS (common unix printing system) - on my QNAP NAS, which is always on, but it seems to be a complicated process that I'm just now embarking on.