move all tickets from one project to another

[trevdude]

Just want to move all the tickets in project A (A is normal Jira)  to project B  - B is service desk

Just want simple steps eg 1- click here and choose this....

[Wazza]

Check out this page, and look for move multiple issues.

[Nic Brough -Adaptavist-]

To add a summary of what you'll find there, it's "search for issues, use bulk edit, and move".

You won't get "one click", as projects can be configured very differently, and JIRA needs to validate the data and change it to match the target configuration.  In a lot of cases, it's going to need to ask you how to change it.