How to assign push API to a dataset

Hello, i have tried microsoft's tutorials and failed to understand how i assign push api to a data set.

I understand that these are the steps : 

• Step 1: Register an app with Azure AD
• Step 2: Get an authentication access token
• Step 3: Create a dataset in Power BI
• Step 4: Get a dataset to add rows into a Power BI table
• Step 5: Add rows to a Power BI table

Now, i managed to register an app, but that's all. The 2nd step is very unclear to me, and to be honest the other steps are too unclear to me. 

I would be grateful for an ellaborate explanation of the steps, and how to do them.

Thank you.