Failing to send Telegram Alert Notification

I am trying to send telegram notification from grafana which is installed on dockers, But its failing to send alert notification.

  • What Grafana version and what operating system are you using?
    grafana version: 8.0.3

  • What are you trying to achieve?
    Telegram Alerting

  • What happened?
    when i checked the logs it shows the below:

t=2021-06-29T09:12:10+0000 lvl=eror msg=“Failed to send webhook” logger=alerting.notifier.telegram error=“Post “https://api.telegram.org/bot1881483576:AAErcZ*********************/sendMessage”: context deadline exceeded (Client.Timeout exceeded while awaiting headers)” webhook=
t=2021-06-29T09:12:10+0000 lvl=eror msg=“failed to send notification” logger=alerting.notifier uid= error=“Post “https://api.telegram.org/bot1881483576:AAErcZ_DP5RpgWoGWs/sendMessage": context deadline exceeded (Client.Timeout exceeded while awaiting headers)"
t=2021-06-29T09:12:10+0000 lvl=eror msg=“failed to send notification” logger=alerting.notifier uid= error="Post "https://api.telegram.org/bot1881483576:AAErcZ_DP5Rp
egWoGWs/sendMessage": context deadline exceeded (Client.Timeout exceeded while awaiting headers)"
t=2021-06-29T09:12:10+0000 lvl=eror msg=“Failed to send alert notifications” logger=context userId=1 orgId=1 uname=admin error="Post "https://api.telegram.org/bot1881483576:AAErcZ_DP5RpPi
**************gWoGWs/sendMessage”: context deadline exceeded (Client.Timeout exceeded while awaiting headers)” remote_addr=10.200.213.211
t=2021-06-29T09:12:10+0000 lvl=eror msg=“Request Completed” logger=context userId=1 orgId=1 uname=admin method=POST path=/api/alert-notifications/test status=500 remote_addr=10.200.213.211 time_ms=30030 size=48 referer=http://nlamyarva12.mtn.co.za:3000/alerting/notification/new

Quick reply will be much appreciated…