Prevent double icons with custom .desktop file in dock

Question

I have created a custom .desktop file to launch Chrome in dark mode.

Here is what the file looks like:

[Desktop Entry]
Name=Dark Chrome
Exec=google-chrome-stable --enable-features=WebUIDarkMode --force-dark-mode
Terminal=false
Icon=/opt/google/chrome/product_logo_64.png
Type=Application

I have added it to the dock. When I launch the application from the dock it creates another separate chrome icon rather than just attaching the process to the existing icon (as a regular application behaves)

How can I get it to behave like a regular application icon?