Is it possible to change or edit tickets while it is raised?

No. The tickets can only be modified by one user at a time. It can be modified once the follow up actions are performed by the workers tagged to the ticket.

See “How do I edit a ticket after submission?” add hyperlink to existing question
A ticket cannot be edited after it is being submitted because it will have to be approved by the approver and followed up by further work processes.

For governance, please raise a new ticket, or ask your approver to reject the ticket for your further modifications.