'Request missing required body param' when submitting front end entry form - Craft CMS - frontend

Question

I'm pretty new to craft and creating my first front end entry form using the demo code provided by craft. For some reason I'm getting a 'Request missing required body param' error. I've tried adding <input type="hidden" name="entryId" value=""> but that didn't solve the issue.
Here's my code:
{% extends "_layout.twig" %}
{% macro errorList(errors) %}
{% if errors %}
{{ ul(errors, {class: 'errors'}) }}
{% endif %}
{% endmacro %}
{# If there were any validation errors, an `entry` variable will be
passed to the template, which contains the posted values
and validation errors. If that’s not set, we’ll default
to a new entry. #}
{% set entry = entry ?? create('craft\\elements\\Entry') %}
{# Add `enctype="multipart/form-data"` to `<form>` if you’re
uploading files. #}
<form method="post" accept-charset="UTF-8" enctype="multipart/form-data">
{{ csrfInput() }}
{{ actionInput('entries/save-entry') }}
{{ redirectInput('viewentry/{slug}') }}
{{ hiddenInput('friends', '2') }}
<input type="hidden" name="entryId" value="">
<div class="mb-6">
<label for="title" class="block mb-2 text-sm font-medium text-gray-900 dark:text-white">Your Dog's Name</label>
{{ input('text', 'title', entry.title, {
id: 'title',
class:'bg-gray-50 border border-gray-300 text-gray-900 text-sm rounded-lg focus:ring-blue-500 focus:border-blue-500 block w-full p-2.5 dark:bg-gray-700 dark:border-gray-600 dark:placeholder-gray-400 dark:text-white dark:focus:ring-blue-500 dark:focus:border-blue-500',
}) }}
{{ _self.errorList(entry.getErrors('title')) }}
</div>
<div class="mb-6">
<label for="featureImage" class="block mb-2 text-sm font-medium text-gray-900 dark:text-white">Feature Image</label>
{{ input('file', 'featureImage', entry.featureImage, {
id: 'featureImage',
}) }}
{{ _self.errorList(entry.getErrors('featureImage')) }}
</div>
<div class="mb-6">
<label for="postContent" class="block mb-2 text-sm font-medium text-gray-900 dark:text-white">Tell us about your dog</label>
{{ tag('textarea', {
id: 'postContent',
name: 'fields[postContent]',
class:'bg-gray-50 border border-gray-300 text-gray-900 text-sm rounded-lg focus:ring-blue-500 focus:border-blue-500 block w-full p-2.5 dark:bg-gray-700 dark:border-gray-600 dark:placeholder-gray-400 dark:text-white dark:focus:ring-blue-500 dark:focus:border-blue-500',
}) }}
{{ _self.errorList(entry.getErrors('postContent')) }}
</div>
<div class="mb-8">
<label for="postCategories" class="block mb-2 text-sm font-medium text-gray-900 dark:text-white">Breed</label>
<select name="fields[postCategories]" id="postCategories">
{# Create a category query with the 'group' parameter #}
{% set myCategoryQuery = craft.categories()
.group('blog') %}
{# Fetch the categories #}
{% set categories = myCategoryQuery.all() %}
{# display post categories #}
{% if entry.postCategories|length %}
<div class="border-t py-2 mb-6">
{% for category in entry.postCategories.all() %}
<a href="{{ category.url }}" class="inline-block border rounded px-2 py-1 text-sm">
{{- category.title -}}
</a>
{% endfor %}
</div>
{% endif %}
{% nav category in categories %}
<li>
<option>{{ category.title }}</option>
</li>
{% endnav %}
</select>
</div>
{#
{% set field = craft.app.fields.getFieldByHandle('postCategories') %}
{{ hiddenInput('fields[postCategories]', '') }}
<select multiple name="fields[postCategories][]">
{% for option in field.options %}
{% set selected = entry is defined
? entry.postCategories.contains(option.value)
: option.default %}
<option value="{{ option.value }}"
{% if selected %} selected{% endif %}
>
{{ option.label }}
</option>
{% endfor %}
</select>
#}
<div class="mb-6">
<button type="submit" class="text-white bg-blue-700 hover:bg-blue-800 focus:ring-4 focus:outline-none focus:ring-blue-300 font-medium rounded-lg text-sm w-full sm:w-auto px-5 py-2.5 text-center dark:bg-blue-600 dark:hover:bg-blue-700 dark:focus:ring-blue-800">Publish</button>
</div>
</form>
{% endblock %}

Answer 1

I didn't realise that the 2 in {{ hiddenInput('sectionId', '2') }} had to be changed for the ID of the channel - not the handle.
For anyone else stuck with this, the ID can be found in the URL when you're editing the channel in the dashboard settings.
More details here >>