Hosting: Jira Cloud
Basic authentication using username and password won’t work on Jira Cloud. You need to generate special token to authenticate in third party sites / applications.
Save your API token and keep it secret. Use it to login to Jira through app
Create an API token from your Atlassian account:
Log in to https://id.atlassian.com/manage/api-tokens.
Click Create API token.
From the dialog that appears, enter a memorable and concise Label for your token and click Create.
Click Copy to clipboard, then paste the token to your script, or elsewhere to save:
For security reasons it isn't possible to view the token after closing the creation dialog; if necessary, create a new token.
You should store the token securely, just as for any password.
Use access token generated.
If you are facing any errors during login, please contact your Jira Administrator to verify if app was installed in Jira
You will see some options allowing you to start working with Jira
Make sure, app is installed on your Jira and have active license: https://psc-software.atlassian.net/wiki/spaces/ECSD365/pages/919535809
At this article you can find answer for following questions:
What can I do when I get error “API Token is invalid” ?