Explanation with example promise, observable and sync pipe

I am looking someone who can explain in detail with example to fetch data via promise, observable and sync pipe from local json and API to show in the table:
Use also some operator like, switchMap , letMep, concatMap

Task:
- Fetch data via promise, observable and sync pipe from local JSON and API and show in the table
- Use also some operator like, switchMap , letMep, concatMap

NOTE: We can use API from https://apipheny.io/free-api/#apis-without-key

Required skills: Angular and Typescript