Can I "close" a customer job in the online version just like the desktop version

You can mark it as completed in your QuickBooks Online (QBO), jaug.

Closing a customer job in the Desktop version is equivalent to marking a project as completed in QBO. I'll show you how:

1. Select the  Projects menu.
2. Locate the project you need to close.
3. In the Action column, click the ellipsis.
4. Hit Mark as completed.

Visit this article for handling projects in the system: Create and manage projects in QuickBooks Online.

You can also run project-specific reports to track the project profitability in QuickBooks.

I'm always prepared to answer all your queries about projects or any QuickBooks-related topics. Kindly keep me updated by leaving a comment below. I'll be sure to provide a prompt response.