I thought it was breeze-icons or qt5-qtquickcontrols and made this MR more than a year ago, but it remained a mystery what is actually missing: https://gitlab.alpinelinux.org/alpine/aports/-/merge_requests/42988

Are you on debian or postmarketOS? Because in "normal" desktop alpine in a VM it could be fixed with apk add breeze-icons, but on postmarketOS on a phone it did not work 🤔