How to programmatically get the Authorization code without requiring the user approval in OAuth 2.0

We are building an backend application (using C# Dotnet) to interact with the JIRA cloud instance. We wanted to use an advanced authentication model instead of the basic auth using a username/API key. Hence, we tried the OAuth 2.0 approach but it looks like we need to have a manual approval to get the authorization code based on the below article. https://developer.atlassian.com/cloud/confluence/oauth-2-3lo-apps/#1--direct-the-user-to-the-authorization-url-to-get-an-authorization-code

We were able to get the authorization code using the callback URL and exchange the authorization code. The only problem in this flow is the manual approval process which needs user interaction.

Please let us know if there is a way to programmatically get the Authorization code without requiring the user approval each time we wanted to interact with the rest API from the Dotnet C# application. We wanted to avoid using the basic auth for security reasons. Also, let us know if there is any other way of secure authentication model to make the JIRA rest API calls.

Thanks