...
Jira Cloud Migration Assistant is a free plugin from Atlassian that is able to make your migration to Jira as easy as possible. It’s able to migrate the data from your Jira instance, but also 3rd party plugins that support this migration platform. Newer versions of Jira include the Jira Cloud Migration Assistant by default. If your server instance doesn’t have it, please install the plugin from Atlassian Marketplace.
...
2. Install the cloud version of
...
Subtasks Navigation
Jira Cloud Migration Assistant (JCMA) allows you to review which applications you want to use in the cloud or find alternatives if the application has no cloud version. As a part of the migration process, you will be prompted to install the cloud version of Subtasks Navigation. It’s not necessary to do it from JCMA though. You can visit your cloud instance any time before the migration and install the cloud version from Atlassian Marketplace.
...