-In your home directory open /.local/share/applications/
-Right click in this folder and create a empty desktop file
-Open this file with gedit and paste this content:

[Desktop Entry]

Type=Application

Icon=user-trash

Name=Trash

Name[de]=Papierkorb

Comment=open trash

Categories=FileManager;Utility;Core;GTK;

Exec=nautilus trash:///

StartupNotify=true

Terminal=false

MimeType=x-directory/normal;inode/directory;

Name[de_DE]=Papierkorb

-Rename the file to trash.desktop
-Restart the GNOME shell with Alt+F2+r
-Type trash in the search and pin it to your Dock.