Some apps don't have browser logins (mobile or desktop only apps) but you still want to manage your passwords in one place (Google Chrome).
Inspect the page and insert the following HTML <form>
anywhere on the page. Then fill it out and submit 🤠
<form id="login" action="/" method="post">
<input type="text" autocomplete="username">
<input type="password" autocomplete="current-password">
<input type="submit" value="Sign In!">
</form>
HTML markup from https://www.chromium.org/developers/design-documents/form-styles-that-chromium-understands