This should correct the package being out of date.

index 9fe46df..feb58bc 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -1,7 +1,9 @@ 
 pkgname=gruvbox-plus-icon-theme
-pkgver=5.5.0 # renovate: datasource=github-tags depName=SylEleuth/gruvbox-plus-icon-pack
+pkgver=6.3.0 # renovate: datasource=github-tags depName=SylEleuth/gruvbox-plus-icon-pack
 pkgrel=2
 pkgdesc="Icon theme based on Gruvbox color scheme"
 arch=(any)
@@ -13,7 +15,7 @@ provides=(gruvbox-plus-icon-theme)
 conflicts=(gruvbox-plus-icon-theme-git)
 options=(!strip !emptydirs)
 source=("$pkgname-$pkgver.tar.gz::$url/archive/v$pkgver.tar.gz")
-sha256sums=('0c03a10607e090e0a1d10a415c8be200b11b9a1bdc46d6e189b0577de0e94339')
+sha256sums=('ab722bed0271eba05d89bf62fe804c80051fe6e21303ce1c331d0e7c4bed8e5e')

 package() {
   cd "gruvbox-plus-icon-pack-$pkgver"
-- 

@fabrixx thanks, it was not working indeed. Fixed!

You have to rearrange subfulders to make available by GNOME Tweak.

If I extract the Gruvbox-Plus-Dark/..Gruvbox-Plus-Dark subfolder and copy it to /usr/share/icons the icons are recognized by gnome-tweaks

But why do I only see the dark version? Shouldn't they all be there?

Thank you 1000 for creating the package!