Hi,
In Jira you can't assign a ticket to multiple assignees. It is not possible to have more than one ticket assignee by default settings, because it is against the Jira principles. The ticket should have one assignee, so there is a single responsibility.
The similar situation is with reporters. The ticket should have one reporter.
If possible, you can split the ticket into multiple sub-tickets and assign them to different users.
Jira ticket can have one assignee and one reporter, but
there is a way how to link multiple users to the ticket.
You can add
custom fields that can be used to link more users to your epics, stories or tasks.
To add a custom field:- Go to the Settings
- Click on Issues
- In Fields section, choose Custom fields
- Click on Create custom field
- Select a field type - depending on your needs choose between User Picker (single user) / User Picker (multiple users)
- Give a name this custom field and write a description
- Click on Create
Created field should appear on the defined types of tickets. You can use this field to link another users to the ticket.