I’m grateful to see you here in the Community, @ankurarora-sme. I’m here to provide a few steps on how to import templates into QuickBooks Online.
Go to the Gear Icon in the upper right-hand corner.
Under Your Company, click on Custom Form Styles.
Click on New Style.
From the dropdown choose Import Style.
Choose Invoice under Pick Your Form Type.
Upload your template. **Note: If this is your first time and you would like some help setting up your template, This includes a catalog of the EZ Map Fields Catalog.
From there, you’ll map your fields so QuickBooks knows what values you want.
When everything looks good, simply click Save and create a name for your new style.
The Import style feature is unavailable to a QuickBooks Online account created after June 29, 2021. Otherwise, you can still upload custom form styles.