I started with SPFx development recently. I packaged a client side web-part as a file helloworld-webpart.sppkg following Microsoft's tutorial. Then I uploaded it to my Apps Catalog site. Though it was uploaded to the Apps Catalog successfully, but it's not available for installation on any of the sites. I tried the gear 'Add an App', tried searching for 'helloworld', but couldn't find it.
Any suggestion/help on this would be much appreciated.