For Photoshop 2023 and above, the easiest way to install Alpaca is simply to get it from Creative Cloud Marketplace, over here!.If that does not work for you, or if you have an older version of Photoshop then continue reading, otherwise you are good to go!
Simply click on the file you downloaded (e.g. alpaca-1.5.1_PS23.ccx). This should open
Creative Cloud and ask you if want to install the plugin locally.
If nothing happens when you double click on the file, quit Creative Cloud
before trying to open the file again.
Once installed, open Adobe Photoshop, and you should see a new tab called
‘alpaca’ with a login screen. You can dock this tab anywhere just like any
other Adobe Photoshop tab.
If you do not see the tab, in Adobe Photoshop, go to Plugins → alpaca and
make sure alpaca is checked.
Unzip (e.g. alpaca-1.5.1_PS23.zip), you should now have a alpaca folder (with a version number
in the name)
Move the alpaca folder in your Adobe Photoshop plugin directory
On MacOS, the plugin folder is located under Applications → Adobe
Photoshop 2022 → Plug-ins
On Windows, the plugin folder should be under C:\Program Files\Adobe\Adobe Photoshop 2022\Plug-ins
Open Adobe Photoshop (if it was already open, restart it), in the menu, under
Plugins you should now see alpaca. Enable it by clicking on alpaca
→ alpaca. Going back into Adobe Photoshop, you should now see an alpaca tab,
you can move it or dock it anywhere and start using alpaca.