How to use the @aws-cdk/aws-sns.Topic.fromTopicArn function in @aws-cdk/aws-sns

environment: {
          DATA_BUCKET: `${bucket.bucketName}`,
          MAIL_NAME: `${mailName}`,
          MAIL_USER: `${mailUser}`,
          MAIL_PASS: `${mailPass}`,
          MAIL_HOST: `${mailHost}`,
          MAIL_PORT: `${mailPort}`,
          MAIL_REPLY_TO: `${mailReplyTo}`,
          DROPBOX_TOKEN: `${dropboxToken}`,
          SNS_TOPIC_ARN: `${snsTopicArn}`,
          SENTRY_DSN: `${sentryDsn}`
        }
      });

      bucket.grantReadWrite(lambdaFn);
      const snsTopic = Topic.fromTopicArn(
        this,
        'SendThatInvoice',
        `${snsTopicArn}`
      );
      snsTopic.grantPublish(lambdaFn);

      // Run every day at 6PM UTC
      // See https://docs.aws.amazon.com/lambda/latest/dg/tutorial-scheduled-events-schedule-expressions.html
      const rule = new events.Rule(this, 'send-that-invoice-cron-rule', {
        schedule: events.Schedule.expression('rate(4 hours)')
      });

      rule.addTarget(new targets.LambdaFunction(lambdaFn));
    } else {
      console.error(
        'It seems you haven\'t set one of your ENV vars correctly, please check below'