Atlassian Api Keys
According to Atlassian in order to use the organizations or user REST API you must have a valid API key and your domain to be verified(your users accounts need to be managed accounts).
https://developer.atlassian.com/cloud/admin/organization/rest/intro/
That is why Timescale needs an API Key to get this data.
STEPS:
To create an API key:
Go to admin.atlassian.com. Select your organization if you have more than one.
Select Settings > API keys.
Select Create API key in the top right.
Enter a name that you’ll remember to identify the API key.
By default, the key expires one week from today. So make sure you change the expiration date to bigger period like an year. This needs to be re generated once per year
Select Create.
Click Done
Copy the API KEY and place it in Timescale/Overall Settings/Atlassian Api Key. Hit Update Button.
9.Verify your domain to manage accounts
https://support.atlassian.com/user-management/docs/verify-a-domain-to-manage-accounts/