schmety

Hi @schmety, hope you're well. Good old Astrobackyard, been following Trevor since the start of this year as I've gotten into astrophotography!
I believe you can approximate the Photoshop workflow by using Select>Select Sampled Colour. Click on the middle of a star, then adjust Tolerance to select the rest (you might have to go up to 100%). Also, you may want to try switching the colour model from RGB to Intensity, as stars will typically be the brightest parts of the image.
Once you've made the selection by clicking Apply, go to Select>Grow/Shrink. Grow the selection by what is appropriate (I ended up with 16px for my image) and check the Circular option for nice round selection marquees around the stars.
Finally, go to Edit>Inpaint and the stars will be removed. This might take a couple of minutes to complete if you're working in 32-bit—which you should be! Not sure if you're aware but Affinity Photo can use practically all of its tools, filters, adjustments etc in 32-bit, so there's no need to tone stretch then flatten and convert to 16-bit. The only time I've needed to use 16-bit is when creating a synthetic flat frame to combat gradients/skyglow etc.
You can also use Select>Tonal Range>Highlights to make the initial selection, but you get less flexibility as there's no Tolerance option. Also, if you're in 32-bit Linear, what constitutes highlight detail will differ from 16-bit Nonlinear, so you may not find all the stars are successfully selected.
Hope that helps!

more like that way

Hi !
I know i can read this topic on several other forums and it was already talked a lot i think, but anyway, 
since here are mostly Affinity users, i'll ask here :)
I have tried now Adobe cloud with Photoshop and Lightroom.
I have installed it for a month now.
But still, not that comfortable than with Affinity.
Since i'm using stacking , panorama a lot, i think Affinity has better interface and a lot easier access to that options, which i like a lot.
I was installed Photoshop mainly , cause i also work with Astro photography and there are a lot of manuals (videos), how to blend 2 photos together (foreground and sky), 
other tips and so on. I also have one plugin for Photoshop (Orion, from Miklywayhunters) which i wanted to try for milkyways and night photos, but didn't find it so usefull, 
also didn't learned a lot so far :)
On other hand , paying monthly for Adobe cloud is quite a lot over years, so Affinity wins. What do you think about that ? Best, Matej

I got a refund for Affinity Designer and i bought Affinity Photo.
So , everything is fine now
Great support, 
Best