Creating multiline comment with API

Multiline comment on merge request with API

I’m trying to use the GitLab REST API to make a comment on multiple lines of the changes of a merge request.

I’ve almost managed to do so using the following json body:

    "position": {
        "base_sha": "4af5230bd8894e9e56a5343537fd0f5dd1d3341b",
        "start_sha": "4af5230bd8894e9e56a5343537fd0f5dd1d3341b",
        "head_sha": "7e5df9ede4766b0c33509881055d00be94debdae",
        "new_path": "test.php",
        "old_path": "test.php",
        "position_type": "text",
        "new_line": 20,
        "line_range": {
            "start": {
                "line_code": "63b0bac63e6a8d4a13fe35e04eac455258e9500b_18_18",
                "type": "new"
            "end": {
                "line_code": "63b0bac63e6a8d4a13fe35e04eac455258e9500b_18_20",
                "type": "new"
        "ignore_whitespace_change": false
    "body": "test comment body"

The comments made using a request like this do seem to span over multiple lines as shown below:

However, it’s missing the part at the top which specifies which lines it spans over, as shown below:

Is there anyway to include that little bit of text using the GitLab REST API?