You will need to create your own service by creating file in /lib/systemd/system folder.
For example:
/lib/systemd/system/myBot.service
Assuming your bot is in /opt/myBot/ folder - put the following lines into that file:
[Unit]
Description=myBot - Telegram bot
After=network.target
[Service]
ExecStart=/opt/mybot/myBot.py
WorkingDirectory=/opt/mybot/
KillMode=process
Restart=always
RestartSec=5
[Install]
WantedBy=multi-user.target
Save the file and enable service:
systemctl enable myBbot
Now - start the service
systemctl start myBot
To check status
systemctl status myBot
To stop bot
systemctl stop myBot
If you happen to edit the service file - reload it by issuing
systemctl daemon-reload