How can I choose image format if paste from 3rd party screen shot app?

Normally I use Cleanshot as my main screenshot app on Mac.

But I found obsidian will always save image as PNG instead of JPG when I shot by Cleanshot, even though I already picked JPG as my output file format in the preference of Cleanshot.

I also tried Typora, when paste any shot from Cleanshot, Typora will save image as JPG.

I emailed to Cleanshot developer for help, got replied as below:

It depends on which application you paste the image into. Unfortunately some apps convert JPG to PNG and there is nothing we can do about it…

So how can I save the format of my choice?

you can’t. if there is not a feature requset open for this already, open a new one.