IP whitelisting

You may need to add the following IP addresses to your allow list if your server has restrictive firewall settings:

159.89.243.216
161.35.249.14
3.135.68.213

Protocol HTTPS, Port 443

Atlassian IPs and domains must also be allowed to ensure that Atlassian Cloud apps and services work as expected

https://support.atlassian.com/organization-administration/docs/ip-addresses-and-domains-for-atlassian-cloud-products/