ERROR: Error while retrieving public keys from API: Cannot send an HTTP request to the Blackfire API.

[kamal2222ahmed]

Following the instructions:

$export BLACKFIRE_SERVER_ID=
$export BLACKFIRE_SERVER_TOKEN=

Status: Image is up to date for blackfire/blackfire:latest
Done
You can now run the containers using the followings :

• For XHProf: docker run --rm -it -v $(pwd):/app tucksaun/blackfire-workshop:xhprof
• For Xdebug: docker run --rm -it -v $(pwd):/app tucksaun/blackfire-workshop:xdebug
• For Blackfire:
  1. docker run -d --name blackfire -e BLACKFIRE_SERVER_ID -e BLACKFIRE_SERVER_TOKEN blackfire/blackfire
  2. docker run --rm -it -v $(pwd):/app --link blackfire:blackfire tucksaun/blackfire-workshop:blackfire

but it does not start:
$ docker run -d --name blackfire -e BLACKFIRE_SERVER_ID -e BLACKFIRE_SERVER_TOKEN blackfire/blackfire
a23abc68f857d697c5695284e3c2d45c3de1e8534c38cd7a7eebabf6a553150a
(base) ✔ ~/QA/BLACKFIRE/blackfire-workshop [master|✔]
08:18 $ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
(base) ✔ ~/QA/BLACKFIRE/blackfire-workshop [master|✔]

so I start in interactive mode:

$ docker run -it --name blackfire -e BLACKFIRE_SERVER_ID -e BLACKFIRE_SERVER_TOKEN blackfire/blackfire
[2019-03-31T12:19:26Z] ERROR: Error sending request to Blackfire API: Get https://blackfire.io/agent-api/v1/public-keys: x509: certificate signed by unknown authority
[2019-03-31T12:19:26Z] ERROR: Error while retrieving public keys from API: Cannot send an HTTP request to the Blackfire API.