add_filter(
    'mastodon_api_submit_status',
    function (
        Enable_Mastodon_Apps\Entity\Status $status = null,
        string $status_text,
        string $in_reply_to_id = null,
        array $media_ids = null,
        string $post_format,
        string $visibility,
        string $scheduled_at = null,
        WP_REST_Request $request
    ) {
        // Your code here
        return $status;
    },
    10,
    8
);

apply_filters( 'mastodon_api_submit_status', null, $status_text, $in_reply_to_id, $media_ids, $post_format, $visibility, $scheduled_at, $request )