Cannot POST / With Post request from non '/' site - html

Question

I am new to Node and am having trouble with the POST functionality.
I have a simple website, where I have the following lines:
app.get('/sign',(req,res)=>{
res.sendFile(path.join(__dirname, 'static', 'index.html'));
});
app.post('/sign', (req,res)=>{
res.send("Success!")
});
The get request works perfectly fine, but when I post the data in the form back, instead of getting a success message, I get Cannot POST /.
When doing the same from the '/' directory with app.get('/', etc.)
it works fine.
This is the content of the 'index.html' file:
<form action = '/' method='POST' id="form">
<div class="form-group">
<label for="emal">Email address</label>
<input type="email" class="form-control" name="email">
</div>
<div class="form-group">
<label for="pwd">Password</label>
<input type="password" class="form-control" name="password">
</div>
<button type="submit" class="btn btn-default">Submit</button>
</form>

Answer 1

The action attribute specifies the URL the form data will be posted to.
You have said to post it to /.
Your server side code provides a route for /sign but not /.
You need your URLs to match. Either change action="/" to action="/sign" to be explicit about where you are posting it to or remove the action attribute entirely so it posts to the current url (which is /sign since that is the route of the GET handler that provided the HTML document containing the form).