How to Bulk Update username by using Jira Cloud

[Ravina]

I want update multiple username at a time by using excel sheet .

[Nic Brough -Adaptavist-]

Do you really mean updating usernames, or do you mean you are trying to select different users in reporter/assignee/custom-user-field/etc?

[Ravina]

No I want to update existing user with new user

[Nic Brough -Adaptavist-]

I'm sorry, but repeating the phrase that I am questioning the meaning of does not explain it.

What is "update new user with existing user"?  What would it actually do?

[Ravina]

I am migrating data from jira server instance to jira cloud instance and both instances using different user management (different user name) users already have account on migrated instance, but there user name are different in both server and cloud instance.

so using script before migration I want to update the jira server username with respect to there cloud instance username.