Packagecloud account seems like out of api requests

I am trying to install grafana on ubuntu and getting following error message:

root@v1:/etc/apt/sources.list.d# apt-get update && apt-get -y install grafana
Err:1 https://packagecloud.io/grafana/stable/debian jessie InRelease
  429  Too Many Requests [IP: 54.215.161.51 443]
Hit:2 https://repos.influxdata.com/ubuntu bionic InRelease
Hit:3 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:4 http://archive.ubuntu.com/ubuntu bionic InRelease
Hit:5 http://archive.ubuntu.com/ubuntu bionic-updates InRelease
Hit:6 http://archive.ubuntu.com/ubuntu bionic-backports InRelease
Reading package lists... Done
W: Failed to fetch https://packagecloud.io/grafana/stable/debian/dists/jessie/InRelease  429  Too Many Requests [IP: 54.215.161.51 443]
W: Some index files failed to download. They have been ignored, or old ones used instead.
Reading package lists... Done
Building dependency tree
Reading state information... Done

OS release

root@v1:/etc/apt/sources.list.d# lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 18.04.3 LTS
Release:	18.04
Codename:	bionic