Installation of Kapacitor failed

I am using InfluxDB shell version: 1.8.0 and Telegraf 1.14.4 (git: HEAD c6fff6d8)

I need to install Kapacitor as well. But I am getting error while I am trying to start the service as follows:
root@database:~# $ sudo systemctl start kapacitor

Failed to start kapacitor.service: Unit kapacitor.service not found.

steps to reproduce:

  1. Download kapacitor binaries for linux 64 https://portal.influxdata.com/downloads/
  2. tar xvfz kapacitor-1.5.5_linux_amd64.tar.gz
  3. Start influxdb with sudo systemctl start influxdb
  4. Start telegraf with sudo systemctl start telegraf
  5. Start kapacitor with sudo systemctl start kapacitor

Return: Failed to start kapacitor.service: Unit kapacitor.service not found.

In the follwing root I can see that the kapacitor.service file exists:
./kapacitor-1.5.5-1/usr/lib/kapacitor/scripts/kapacitor.service