Create a remote issue
In the operation creation page, when a remote Jira server is selected in the "Server" field of the "Target" tab, the Copy & Sync operation will create and link a new issue on a second JIRA instance, that is to say a remote server.
Prior to configuring such an operation, an Application link between the two JIRA environments must be set up. Once done, a specific Fields Mapping for this operation must be configured.
Potential compatibility issues with Application Links: Problems after upgrading to Jira 10: Impossible to retrieve data from target remote server
In this page, we will explore the options available when creating a remote Jira issue.
Issue context
The "Issue context" section of the tab offers the following options:
Issue Context for remote Jira creation operation
Project : select the target project where the operation will be created (or a project category).
If you select a project category, the user will have the choice to select a target project from all projects contained into this category.
Issue type : select the issue type of the newly created issue.
Link : If the box is checked, then the two issues will be linked by a basic JIRA link.
It is not possible to select the link type for Remote links.
The fields can be locked as for a Local JIRA issue creation in the pop-up window thanks to 
buttons.
Issue content
The "Issue content" section of the tab offers the following options:
Fields mapping : select a mapping which will pre-fill some of the available fields on the issue creation screen. This field is mandatory.
Attachments : choose whether to copy attachments to the newly created issue. Maximum allowed size is 10MB.
Update source fields : the fields which are selected here will be populated by the configured value on the source issue.
If the remote JIRA issue creation is supposed to be launched during a post-function, make sure all the mandatory fields are filled in.
Summary is basically a mandatory field
Depending on the remote JIRA platform configuration, some other fields might be necessarily filled in
Be sure as well that the Project and Issue type fields are filled in the operation target configuration.