How to write a struct in storage?

heyy guys, running into a problem

I have this code :

   member token_address : felt
   member drip_amount : Uint256
   member balance : Uint256
end

@storage_var
func tokens_ledger(index : felt) -> (tokenLedger : TokenLedger):
end```

```let (ledger : TokenLedger) = TokenLedger(token_address, drip_amount, balance)
tokens_ledger.write(index, ledger)```
But am getting this error :

```faucet.cairo:94:34: Unexpected '.' after '__main__.TokenLedger' which is struct.
let (ledger : TokenLedger)  = TokenLedger(token_detail.token_address, token_detail.drip_amount, curr_balance)
                                ^*********^

       Failed

Error in plugin Starknet: Failed compilation of 1 contract.```