Running into 401: Access Denied exception

[SURYASPR]

Hi, I'm using Atlassian.SDK.AspNetCore nuget package and .NET 7 version. I'm trying to get an issue information using the following code:

using Atlassian.Jira;
var jiraRestClient = Jira.CreateRestClient(url, username, password);
Issue issue = await jiraRestClient.Issues.GetIssueAsync(IssueKey);

But this is running into following exception:
System.Security.Authentication.AuthenticationException
HResult=0x80131501
Message=Response Content:

401: Access Denied

Source=Atlassian.Jira
StackTrace:
at Atlassian.Jira.Remote.JiraRestClient.GetValidJsonFromResponse(IRestRequest request, IRestResponse response)
at Atlassian.Jira.Remote.JiraRestClient.d__11.MoveNext()
at Atlassian.Jira.Remote.IssueService.d__18.MoveNext()

Can you please help me on this ?