Migration from another task management tool

Hello,

We are using another management platform and we want to move to JIRA.
We have a backup of our task / project / attachments.

I create an API Token with “basic” on my account (org admin) and i am able to create issue and post attachment with REST API.

Unfortunately I have the following problem: I can’t create comments or work log for other users.

I read documentation :

https://developer.atlassian.com/cloud/jira/platform/security-overview/
https://developer.atlassian.com/cloud/jira/platform/oauth-2-3lo-apps/
https://developer.atlassian.com/cloud/confluence/user-impersonation-for-connect-apps/

And topics :
https://community.developer.atlassian.com/t/seeking-clarification-around-act-as-user-scope-and-related-actions/71724

Or tickets :
https://ecosystem.atlassian.net/browse/AC-1080

So i create and “App with oAuth 2.0” and i’m able to obtain a bearer token with oAuth process, it’s look like it’s woking because i have result here :

https://api.atlassian.com/oauth/token/accessible-resources

[{
        "id": "xxxxx-xxxxx-xxxx-xxxxx-xxxxx",
        "url": "https://xxxxxxxxxxx.atlassian.net",
        "name": "xxxxxxxxxxx",
        "scopes": "manage:jira-project","manage:jira-configuration","read:jira-work","write:jira-work",
        "avatarUrl": "https://site-admin-avatar-cdn.prod.public.atl-paas.net/avatars/240/triangle.png"
    }
]

And https://api.atlassian.com/me works too.

But i can’t get issues when i make some call, example https://api.atlassian.com/ex/jira/xxxxx-xxxxx-xxxx-xxxxx-xxxxx/rest/api/2/issue => {“code”:401,“message”:“Unauthorized; scope does not match”}.

And how do you then make calls to create comments “as another user”?

Thanks a lot

Yathus