Define dpi and resolution in Darktable

I need to deliever some images that I have taken and processed from raw images. I have clear instructions to deliver images the with 300 dpi at 210 x 297 mm, in either TIFF or JPEG format.
However, there seem to be no settings for this in darktable. Is there any simple way to set this as export for a couple of images?

Convert 210mm x 297mm to inches, multiply by PPI, resize accordingly.

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If you really need images at DIN A4 size, create a new image in gimp with 210 x 297 mm at 300 ppi. Then open your image and paste it as a new layer. Scale the layer, so that the image fits the canvas. Export from gimp as JPEG or TIFF.

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210mm x 297mm
= 8,267inch x 11,693inch
*300ppi (ppi = pixel per inch)
= 2480px x 3508px

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ok, thanks for the info. Would be great if this could be made more obvious in the darktable export dialogue.

For raster editors like darktable the real world units (mm) and the conversion to them (PPI) are mostly useless, so we never bothered to add anything like that.
That being said, if you also require to set the DPI value in the images’ metadata there is a setting metadata/resolution in ~/.config/darktable/darktablerc which already defaults to 300.