Unable to install plugins with cli

I have set HTTP and HTTPS proxies. plugins list-remote works but plugins install generates this error.
What am I doing wrong?

[root@server ~]# grafana-cli plugins install savantly-heatmap-panel
installing savantly-heatmap-panel @ 0.2.0
from: https://grafana.com/api/plugins/savantly-heatmap-panel/versions/0.2.0/download
into: /var/lib/grafana/plugins

Error: ✗ failed to download plugin archive: Failed to send request: Get https://codeload.github.com/savantly-net/grafana-heatmap/legacy.zip/d2244abb0e46f5b31a5818a3bec5c1101075e1c8: Forbidden

It worked for me locally so seems like it must be something to do with your proxy settings or firewall settings.