from bs4 import BeautifulSoup


def parse_object_properties(html):
    """
    Extract key-value pairs from the HTML markup.
    """
    if isinstance(html, bytes):
        html = html.decode('utf-8')
    page = BeautifulSoup(html, "html5lib")
    propery_ps = page.find_all('p', {'class': "list-group-item-text"})
    obj_props_dict = {}
    for p in propery_ps:
        if 'data-name' in p.attrs:
            key = p.attrs['data-name']
            value = p.get_text().strip()
            obj_props_dict[key] = value
    return obj_props_dict