You need administrator rights in Jira to perform the tasks on this page.
To add the Checklist Proxy for Customer Portal custom field:
Go to Administration > Issues.
In the sidebar, go to Fields > Custom fields.
Click Add custom field.
In the window that opens, select the Checklist Proxy for Customer Portal field type and click Next.
Enter a name and description for the new Checklist Proxy for Customer Portal custom field and click Create.
On the Associate field [name] to screens page that automatically displays, select the screens on which the new Checklist Proxy for Customer Portal custom field should appear and click Update.
The Checklist Proxy for Customer Portal custom field is meant to be shown on the customer portal and will not provide relevant information on regular Jira screens. You need to associate the field with the Create screens for it to be displayed on the customer portal, but the field will not be visible when creating issues using Jira’s regular Create Issue dialog.
The new Customer Portal custom field will now be listed on the Fields > Custom fields page, which can be accessed through the sidebar.