Currently I\'m accessing JIRA API in C#.Net application with username and password. But I need to access the JIRA API without entering a username and a password even without has
Best approach for this is to read the documentation of the JIRA version you are using, since different versions could have different ways to approach Rest APIs.
For me below endpoint worked with Basic auth:
curl -u username:password -X GET -H "Content-Type: application/json" http://localhost:8080/rest/api/2/issue/createmeta