How to use the aws-amplify.I18n.get function in aws-amplify

showComponent(theme) {
		return (

showComponent(theme) {
        if (this.checkCustomSignUpFields()) {
            this.signUpFields = this.props.signUpConfig.signUpFields;
        }
        this.sortFields();
        return (
            
                
                    <header>{I18n.get(this.header)}</header>

theme={theme}
					key={'phone_number'}
					onChangeText={text => this.setState({ phone_number: text })}
					label={I18n.get('Phone Number')}
					placeholder={I18n.get('Enter your phone number')}
					keyboardType="phone-pad"
					required={true}
				/>
			);
		} else {
			return (
				 this.setState({ username: text })}
					label={I18n.get(this.getUsernameLabel())}
					placeholder={I18n.get('Enter your username')}
					required={true}
				/>
			);
		}
	}

if (!unverified) {
            logger.debug('no unverified contact');
            return null;
        }

        const { email, phone_number } = unverified;
        return React.createElement(
            View,
            { style: theme.sectionBody },
            React.createElement(
                Picker,
                {
                    selectedValue: this.state.pickAttr,
                    onValueChange: (value, index) => this.setState({ pickAttr: value })
                },
                email ? React.createElement(Picker.Item, { label: I18n.get('Email'), value: 'email' }) : null,
                phone_number ? React.createElement(Picker.Item, { label: I18n.get('Phone Number'), value: 'phone_number' }) : null
            ),
            React.createElement(Button, {
                title: I18n.get('Verify'),
                onPress: this.verify,
                disabled: !this.state.pickAttr
            })
        );
    }

showComponent(theme) {
		if (this.checkCustomSignUpFields()) {
			this.signUpFields = this.props.signUpConfig.signUpFields;
		}
		this.sortFields();
		return (
			
				
					<header>{I18n.get(this.header)}</header>

submitBody(theme) {
		return (
			
		);
	}

return (

render() {
        const { authState, hide, federated, onStateChange } = this.props;
        if (!['signIn', 'signedOut', 'signedUp'].includes(this.props.authState)) {
            return null;
        }

        const theme = this.props.theme || AmplifyTheme;
        return React.createElement(
            View,
            { style: theme.section },
            React.createElement(
                Header,
                { theme: theme },
                I18n.get('Sign In')
            ),
            React.createElement(
                View,
                { style: theme.sectionBody },
                React.createElement(Username, {
                    theme: theme,
                    onChangeText: text => this.setState({ username: text })
                }),
                React.createElement(Password, {
                    theme: theme,
                    onChangeText: text => this.setState({ password: text })
                }),
                React.createElement(Button, {
                    title: I18n.get('Sign In'),
                    style: theme.button,
                    onPress: this.signIn,

{I18n.get('Change')}
                    
                
                
                     this.changeState('signIn')}>
                        {I18n.get('Back to Sign In')}
                    
                
            
        )
    }
}

const Footer = props => {
    const theme = props.theme || AmplifyTheme;
    return React.createElement(
        View,
        { style: theme.sectionFooter },
        React.createElement(
            LinkCell,
            { theme: theme, onPress: () => onStateChange('signIn') },
            I18n.get('Back to Sign In')
        )
    );
};