for fetching data, you can use those API /RPC methods.

But on the other hand, I will like to recoomend using:
https://testnet.dton.io/
https://dton.io/

I asked a similar question on the tg group -

The following should work as a chainlink equivalent, since they allow you to run offline computations-
https://docs.orbs.network/v3/orbs-lambda/step-by-step-overview