Log into your Jira instance as an Administrator.
In the upper right corner, click Settings ( ⚙️ ) and select Apps.
In the left-hand panel, click Jira Misc Custom Fields.
Click My custom fields.
In the upper right corner of the window, click New custom field. The Create Custom Field wizard will open.
Name the custom field and, optionally, enter a Description (Point 1, Figure 1, right). The Name and Description will appear in the My custom fields administration screen.
Select the type of custom field you want to create (Point 2, Figure 1, right). See Custom Fields for more information on the various types of fields that you can create.
Click Next.
Select the Jira screens to which the custom field should be added (Point 3, Figure 2, right). Screens can be added individually, or use the checkbox at the top of the column to select all screens.
Click Next.
Set the configuration options for the field (Point 4, Figure 3, right). Depending on the type of field chosen the options will vary; refer to the specific field type documentation for more information on its options.
Click Save.
A custom field can be added to additional screens and contexts after it has been created!
Your new custom field is now ready! When a custom field is first created, it is added to the Jira screens selected in the Wizard, but also to all contexts of your Jira project. If a custom field should only be available to specific issue types or specific projects (or a combination of these), you must update the configuration of the custom field. See https://support.atlassian.com/jira-cloud-administration/docs/configure-custom-field-context/ for more information.
