Which type of beetle?

Unfortunately very bad to see.

Can it be bread beetle?

https://www.google.de/search?hl=de&q=Stegobium+paniceum&tbm=isch&source=lnms&sa=X&ved=2ahUKEwjn-KT_oLeAAxXezgIHd-bAn0Q0pQJegQICxAB&biw=1196&bih=650&dpr=136

These beetles are really very small (up to 3mm), and their larvae unfortunately not only eat bread (and other foods), as their name suggests, they also go to paper, leather and cardboard – books – so the larvae of the bread beetle is also called booksworm.

The larvae eat dry food such as bread, rolls, book covers, spices (chili), legumes, cat food, herbal teas, leather, flour, noodles, products of grain including Salt pastries, soup cubes, chocolate, pet food, dry fish. Packaging made of cardboard or plastic film are pierced. The beetles drill round holes, big like pin heads into the food. The larvae convert food into lumps.

https://www.bio-gaertner.de/ Plant Diseases/Brotkaefer

The bread beetle also damaged wallpaper from whose glue he feeds, and is one of the poorest pests in libraries.

https://fleschhut.de/schaedlingslexikon/brotkaefer/

Thus, one should examine all these things in the room in which they occur exactly after further beetles and also larvae.

Grain pillows, gingerbread hearts, forgotten cookies, animal dry food and spices, please do not forget.

https://www.ungeziefer-und-schaedlinge.de/mittel-gegen-brotkaefer-bekaempf.php

https://de.wikipedia.org/wiki/Brotk%C3%A4fer