Here we will discuss how we can use Microsoft Flow Copy files from one SharePoint Online account or folder to another. 

If you are new to Flow you can check out the below posts:
- Working with Microsoft Flow in SharePoint Online Office 365 and Demo on Send a customized email when a new SharePoint list item is added

- Microsoft Flow Send approval email when a new item is added demo

- How to check for error in Microsoft Flow in Office 365?

To work with the Flow template: Login to the Microsoft Flow Official site.

Then go to the template section and search for "Copy files from one SharePoint Online account or folder to another" Flow template.

Then click on Use this template button like below:

Then we have to give permission, once the required permissions has been given the Continue button will enable. Click on that.

Now in the When a file is created section, give the source site URL and the document library name. You can choose the document library by clicking on the Folder icon in the text box.

Then in the Create file choose the destination site URL as well as the destination document library name. Both looks like below:

Then click on Create flow button like below:

Then click on Done.

Test the Flow:
Here we have created two document library in the same SharePoint online site.

Now to test the Flow, open MyDocumentLib1 and upload document(s) to the document library.

Then automatically the document will be created in the MyDocumentLib2 library.

Test in different sites:
We can also configure to copy document from one SharePoint online site to another SharePoint online site.

From the My Flow page click the particular workflow to edit the workflow.

Here we have changed the Create file section and have put the other site URL and the document library name like below:

Then you click on the Update button to update the workflow.

Now if you will go to the source document library and upload another document. Here we have added MyDemoDocument-Test-2.docx.

Now if you will visit to the destination document library which is presented in another site, you can see the document will be created like below: