On Sharepoint Online we have two different sites.
First site is created throught Office 365 Group. So, we created Office 365 group and sharepont site is created automatically with various web parts available (Planner, Connectors,...)
Second site is "regular" team site and in that team site we are missing those webparts. Please check images.
In apps there are no those apps. How to add all webparts from first site to team site?
Group site web parts
Team site web parts