Are you looking the add the info as metadata or directly on the app? If metadata, then you want an EXIF editor. This one is very basic but may be what you are looking for:
There is another option I see, “Image Toolbox” from F-Droid. This is a broader image tool, and it seems to be leaning into the AI features a bit heavy which may not appeal but there you go!
Late reply, but using Aperture if it is just location that was missing, (timestamp should already be embedded in photo metadata) it is available in the settings. But good to see this is also available in OpenCamera (it has more features than Aperture, but do check your default resolution / compression settings, at least in the past they were very low resulting in fuzzy pictures even with higher end cameras).
Aperture is the default camera app, I had assumed that was the one you were using at the beginning that was not saving location data? (which again is off by default but can be enabled)
This is where I am confused? If I take a photo with Aperture, then in the “recent photo / preview” if I tap on that it does show date and time taken? If you then open in the Gallery it also shows date and time by default? This is why I was suggesting all sorts of complicated tools, I assumed it was something beyond this that you wanted? Maybe there is a problem here somewhere…
But also Open Camera is just fine so if you are happy with it then maybe there is no more need to sort this out?