Hi there, @Abdul Rehman.

Currently, the Edit option for Imported Custom Form Styles are unavailable in QuickBooks Online. As a workaround, we can re-import the designs and add your company info to highlight your brand.

Here's how:

1. Go to the  Gear icon ⚙, then select Custom Form Styles.
2. At the top right, click the New style ▼ drop-down menu, then choose Import style.
3. Select a form type.
4. Click the Save and upload your file field, then locate your DOCX template.
5. Hit Next.

The Custom form styles with multiple pages are not supported. However, your final invoice can take multiple pages depending on the number of line items you enter.

For more information, see this article:Import custom form styles for invoices or estimates.

I’ll be sending feedback on your behalf about the Edit option for Imported Custom Form Style for consideration in future updates. We take customer’s suggestions as an opportunity to guide us on which area of the product we need to improve on.

I'll be right here if you need further help. Have a great day!