[IONIC 3]:How to implement in-app-purchase for video content?

I have developed a app which contains training videos(uploaded by admin in seperate portal). And
i have created in-app-products in google playstore. How to connect those?

The objective:

Admin perspective:
upload video with price or put in app puchase produt id there.

User perspective:
User can pay for each video through in-app-purchase(One time payment).