Calling a smart contract action about eos-go HOT 2 OPEN

        transferPermissionLevel, err := eos.NewPermissionLevel(from + "@active")
	if err != nil {
		panic("Error creating permission level")
	}	
         // Fills in the transaction header information like ref block, delays and expiration is set to 30s
	txOpts := &eos.TxOptions{}
	err = txOpts.FillFromChain(context.Background(), api)
	if err != nil {
		panic("Error filling tx options")
	}

	trx := eos.NewTransaction([]*eos.Action{
		{
			Account:       eos.AN(contractName),  // The contract that will execute the action
			Name:          eos.ActN("addopname"), // The action name
			Authorization: []eos.PermissionLevel{transferPermissionLevel},
			ActionData: eos.NewActionData(OperationNamePost{
				op_id:         1,                 //eos.Uint64
				op_name:       "aaa",             //string
				fields:        fields,            //[]string
				types:         types,             //[]string
				offchain_data: eos.Checksum256{}, //eos.Checksum256
			}),
		},
		}, txOpts)

		// keyBag := eos.NewKeyBag()
		keyBag := &eos.KeyBag{}
		err = keyBag.ImportPrivateKey(context.Background(), fromPrivateKey)
		if err != nil {
			panic(fmt.Errorf("import private key: %w", err))
		}
		api.SetSigner(keyBag)

		_, packedTx, err := api.SignTransaction(context.Background(), trx, txOpts.ChainID, eos.CompressionNone)
		if err != nil {
			panic(fmt.Errorf("sign transaction: %w", err))
		}
		response, err := api.PushTransaction(context.Background(), packedTx)
		if err != nil {
			panic(fmt.Errorf("push transaction: %w", err))
		}

		fmt.Printf("Transaction [%s] submitted to the network succesfully.\n", hex.EncodeToString(response.Processed.ID))