LoginviaPost: impossible to proceede


I am trying to use this app: https://github.com/nextcloud/loginviapost
I created a form as follows: (I had to include a space because it wasn’t marked as a code)

< form method=“post” action="{NEXTCLOUD_LINK}/index.php/apps/loginviapost/login" id=“login_files” >
< input type=“text” name=“username” value=“username”>
< input type=“text” name=“password” value=“password”>
< input type=“submit” value=“Login files” />
< /form >

Sadly, when I click on it, this is what I get:

and this is my error logs:

BUMP ? @system @jospoortvliet ?

No clue, sorry. Ask the developer behind it?