Bad Request

# Pastebin Rk0F4pzJ
DataSetFetcherElement(server_url="https://labs.api.listenbrainz.org/similar-artists/json",
                                     max_num_items=5,
                                     json_post_data=[{
                                         '[artist_mbid]': ",".join(artist_mbids),
                                         'algorithm': "session_based_days_1800_session_300_contribution_3_threshold_10_limit_100_filter_True_skip_30"
                                     }])
Failed to generate playlist: Cannot fetch first dataset recordings from ListenBrainz. HTTP code 400 (<!doctype html>
<html lang=en>
<title>400 Bad Request</title>
<h1>Bad Request</h1>
<p>Required parameter &#x27;artist_mbid&#x27; missing in row 0.</p>