Function comment_post_url 

fn comment_post_url(
    base_url: &str,
    issue_key: &str,
    format: CommentBodyFormat,
) -> String

Free platform comment endpoints (official Cloud/Server REST — no Marketplace).

Host	Format	Endpoint
Server/DC	wiki string	POST /rest/api/2/issue/{key}/comment {"body":"wiki"}
Cloud Free	ADF	POST /rest/api/3/issue/{key}/comment ADF body object

See developer.atlassian.com Cloud platform REST (issue comments) and Server REST API examples. Auth: Cloud email+API token Basic, or Server PAT header.