Adding data to offchain-storage from running asynchronous task.

[haider-rs]

Hey i want to add data to offchain-storage from asynchronous task running in task_manager. i tried to use runtime_api to get access to pallet calls and then tried adding data to offchain_storage but its not working as expected.

 Thread 'tokio-runtime-worker' panicked at 'Accessing a forbidden API: local_storage_set. No: OFFCHAIN_DB_WRITE capability.', /Users/abc/.cargo/git/checkouts/substrate-7e08433d4c370a21/7c195bf/primitives/core/src/offchain/mod.rs:520

my main concern is to add data onchain db and for that, I am trying to use offchain_worker for submitting transactions.
By task_manager_service -> runtime_api -> pallet_call(add offchain_data) -> offchain_worker(getdata) -> submit extrinsic.

Any guide how can i achieve my end goal or any working approach for this problem?

[haider-rs]

we can pass backend client which exposes a interface to offchain worker for our tasks and we can use them instead.