Every modder likes to have free textures/pictures without license hassle. Sadly pixabay does no longer provide public domain pictures
and their new license is not compatible with opensource licenses!!!
But there is a new source now:
( and another working clone: https://www.maxpixel.net/
I think it has tons of the former pixabay textures with the good old CC0-license. Better use this source now, so wou will get no license trouble.
Btw other texture sources are: https://duion.com/art/mainhttps://burningwell.org