error on function call

I moved my form from the template to a view.I still have the same issue.
<form action="<?= base_url('/index.php/Users_start_login/get_email') ?>" method="POST">
<div class="field">
<label class="label">Email Address</label>
<div class="control">
<input id="email" name="email" class="input" type="email" placeholder="Type the email address">
</div>
</div>
<div class="field is-grouped">
<div class="control">
<button class="button is-link">Enter system</button>
</div>
</div>
</form>

I get to the method, get_email, through the form action. Then everything goes crazy.

proof that an old dog can learn new tricks