Craft CMS edit entry link

edit-this.twig

{% if entry is defined and currentUser and currentUser.can('editEntries:' ~ entry.id) %}
  <a href="{{ entry.cpEditUrl }}" class="edit-this section-{{ entry.sectionId }}">Edit this</a>
{% endif %}

Put this file in a partials folder and include it wherever you need an edit link.

Example _entry.html:

{% extends "_layout" %}

{% block content %}
  <article>
    <h1>{{ entry.title }}</h1>
    {{ include 'partials/edit-this' }}
    <p>Posted on {{ entry.postDate.format('F d, Y') }}</p>
    {{ entry.body }}
  </article>
{% endblock %}