How to use the react-native-nfc-manager.requestNdefWrite function in react-native-nfc-manager

_requestFormat = () => {
        let {isWriting} = this.state;
        if (isWriting) {
            return;
        }

        this.setState({isWriting: true});
        NfcManager.requestNdefWrite(null, {format: true})
            .then(() => console.log('format completed'))
            .catch(err => console.warn(err))
            .then(() => this.setState({isWriting: false}));
    }

_requestNdefWrite = () => {
        let {isWriting, urlToWrite, rtdType} = this.state;
        if (isWriting) {
            return;
        }

        let bytes;

        if (rtdType === RtdType.URL) {
            bytes = buildUrlPayload(urlToWrite);
        } else if (rtdType === RtdType.TEXT) {
            bytes = buildTextPayload(urlToWrite);
        }

        this.setState({isWriting: true});
        NfcManager.requestNdefWrite(bytes)
            .then(() => console.log('write completed'))
            .catch(err => console.warn(err))
            .then(() => this.setState({isWriting: false}));
    }