Adding a link to the project sidebar is not work

I try to adding a link to the project sidebar, but it is not work。
so I want some help。
my atlassian-plugin.xml looks like this:

This is a TestCase

product
/projects/$pathEncodedprojectKey?selectedItem=com.atlassian.jira.jira-projects-plugin:TestCasePanel

my project sidebar looks like this:
I do not know why the link is not in the sidebar.
image

but when I try to visit this link ,it is works

atlassian-plugin.xml:

Hello lvzhongwen,

I guess your intent is to create a project tab panel. You might use https://developer.atlassian.com/server/jira/platform/project-tab-panel/ instead of using web-item/web-panel. This one always works for me. :slight_smile:
If there is any reason, why you want to use these modules instead, I recommend to check Jira log files, you may find some exceptions there.

Hope it helps.
Kind regards,
Markéta