Microsoft is continuously adding new features to modern document libraries in SharePoint Online (SPO). One of the latest additions is the integration with Flow (released in Office 365 First Release tenants):
In the top actions bar for a document library, we will see the Flow action from where we can create new Flows or review existing ones:
First option provides access to Flow panel where we can choose any of the existing Flow templates to create a Flow or create a template from scratch:
Second option provides access to the Flow Admin Center where we can see any other Flow we have authored and also Team Flows.