Add note about cross site cookies browser limitation to Jira App page

app/views/jira_connect/subscriptions/index.html.haml

@@ -24,5 +24,14 @@
         %td= subscription.created_at
         %td= link_to 'Remove', jira_connect_subscription_path(subscription), class: 'remove-subscription'
 
+%p
+  %strong Browser limitations:
+  Adding a namespace currently works only in browsers that allow cross site cookies. Please make sure to use
+  %a{ href: 'https://www.mozilla.org/en-US/firefox/', target: '_blank', rel: 'noopener noreferrer' } Firefox
+  or
+  %a{ href: 'https://www.google.com/chrome/index.html', target: '_blank', rel: 'noopener noreferrer' } Google Chrome
+  or enable cross-site cookies in your browser when adding a namespace.
+  %a{ href: 'https://gitlab.com/gitlab-org/gitlab/-/issues/263509', target: '_blank', rel: 'noopener noreferrer' } Learn more
+
 = page_specific_javascript_tag('jira_connect.js')
 - add_page_specific_style 'page_bundles/jira_connect'

changelogs/unreleased/263509_add_cross_site_cookies_browser_limitaion_message.yml

+---
+title: Add note about cross site cookies browser limitaion to Jira App page
+merge_request: 44898
+author:
+type: fixed

doc/integration/jira_development_panel.md

@@ -263,7 +263,7 @@ The GitLab for Jira App uses an iframe to add namespaces on the settings page. S
 
 > "You need to sign in or sign up before continuing."
 
-In this case, enable cross-site cookies in your browser.
+In this case, use [Firefox](https://www.mozilla.org/en-US/firefox/), [Google Chrome](https://www.google.com/chrome/index.html) or enable cross-site cookies in your browser.
 
 ## Usage