stuck

If you can't locate it, that means you have installed the MSIX version of Photo. You can either continue to use the MSIX version and use the aflaunch.exe utility: Or you can uninstall the MSIX version and install the MSI/EXE version.

If you have a version of Nik Collection that includes Nik Perspective or DxO ViewPoint (which is what Nik Perspective actually is) you might find that will do what you want if you experiment with the volume deformation options.

I may be wrong but I've always understood that using Document>Convert did as it implies, it converts the colour space from one profile to another BUT in the export dialog, selecting a different ICC profile would simply assign that new profile to the file, where 'convert' and 'assign' as as defined here:

In years gone by DxO have always discounted all their software over the Black Friday period. What they won't tell you is whether or not this year's discount will be more than the 20% on offer via this freebie.

One thing to note is that although Nik Perspective is part of Nik Collection 6 and is installed as part of this freebie, it is not available as a plugin in AFP. It does work as a stand alone application though.

That's not a problem for me, this v6 freebie will be more than I need for a while. I bought the first version of Nik released by DxO (in 2018??) but have never bothered to update it as I found the only plugin I was using was Silver Efex so it just wasn't cost effective to upgrade. I've now installed this freebie on both my desktop PC and my laptop. The activation code has worked in both cases. That's another result!

'appear' is the key word there. I too followed the link, entered my email address and nothing seemed to happen, except ending up at the DxO Shop. I too thought, "Oh well, nothing ventured, nothing gained." That was then but... Today I got an email, all in German, with a link to download Nik 6. The email also included an activation code. The first thing the installer Did was to ask for the language I wanted to use,but English seemed to be the default. It then recognised my Photolab an Affinity Photo installations. It completed without error and when I opened Photo, all the Nik 6 plugins were available within Photo. Result!

You'll get a better starting point if you explore the options in the scanner and get it to produce TIFFs, rather than JPEGs.

That will be OK until the next update of Photo. When that happens the location will change, meaning you will have to do this all again. The suggestion by @Pšenda to use the MSI/EXE version of Photo rather than the MSIX version will avoid the need to repeat this after the next update.

It also works for Canon .CR3 files.

The instructions work on Windows (10).

I'd strongly advise you to keep your original RAW files.

If you are on Windows then it sounds like you have installed the MSIX version. Read about that here:

I have a 100% Adobe RGB compliant monitor that it is hardware calibrated and profiled. With the monitor using that hardware profile then I get good colour consistency when I: Use DxO PhotoLab to process my RAW file. In PL, use the DxO Wide Gamut (which according to DxO is similar to Rec. 2020) colour space. Export from PL to a 16 bit TIFF with an embedded Adobe RGB profile. In Affinity Photo 2, with it's working colour space is set to Adobe RGB. Print from Affinity to a decent (but not pro) six colour Epson printer. Alternatively, if my final image is for sharing electronically then step 5. becomes: 5. Convert the document from Adobe RGB to sRGB, using perceptual rendering intent and black point compensation. EDITED TO ADD: DxO say their wide gamut is similar to Rec. 2020 on this page, in the first paragraph under the heading immediatley below Fig 10: https://www.dxo.com/news/white-paper-wide-gamut/

What happens if you export your highlight recovered RAW file to a 16 bit TIFF? Are the recovered highlights preserved?