Adding <label> with BeautifulSoup

You can use the .append() function:

label = soup2.new_tag('label')
label['for'] = "cb1"
label['class'] = "indented-checkbox-text"

label.append("Add to favorites")

input.insert_after(label)

Source: https://www.crummy.com/software/BeautifulSoup/bs4/doc/#navigablestring-and-new-tag

You can add whole BeautifulSoup() after a Tag:

from bs4 import BeautifulSoup

html_doc = """
<input id="cb1" type="checkbox"/>
"""

soup = BeautifulSoup(html_doc, "html.parser")
inp = soup.select_one("#cb1")

inp.insert_after(
    BeautifulSoup(
        '\n<label class="indented-checkbox-text" for="cb1">Add to favorites</label>',
        "html.parser",
    )
)

print(soup)

Prints:

<input id="cb1" type="checkbox"/>
<label class="indented-checkbox-text" for="cb1">Add to favorites</label>