Look for the POWER icon in your Chrome browser and click on it.

If the Dialer is sitting in your Chrome tabs, clicking on this will show/hide the Dialer.

If your Dialer is a window, the Dialer will be opened/focused on.

IF TABS ARE OPEN AFTER DIALER STARTS

When using the Dialer within your Chrome tabs, any tab that is open after the Dialer launches will have to be refreshed. Avoid this by using the window/panel option.

NOT ALL TABS ALLOW EXTENSIONS

Some Chrome tabs don't allow the Dialer to load into them. Avoid this by using the window/panel option.