There are several ways to install plugins for Photoshop:
1) When the plugin comes with the installer and during installation it is necessary to specify the path to the directory with the Photoshop plugins, specify C:\Program Files\Adobe\Adobe Photoshop\Plug-ins
2) When the plug-in with the installer is simply installed in the C:\Program Files\ directory, open its directory after installation, look for the file with the * .8bf extension and manually copy it to C:\Program Files\Adobe\Adobe Photoshop\Plug-ins
3) Option when the plugin is without an installer, just copy it to C:\Program Files\Adobe\Adobe Photoshop\Plug-ins
The directory C:\Program Files\Adobe\Adobe Photoshop\Plug-ins may be slightly different, depending on the bit depth of the operating system (32 or 64 bits), for example C:\Program Files (86)\Adobe\Photoshop\Plug-Ins\, as well as looking where Photoshop was installed, but finding a directory with Photoshop in it must have Plug-ins.
Also, opening Photoshop, you can go to the settings, namely, Edit – Preferences – Plug-Ins and manually specify the directory for placing plug-ins.