title: Add button Preview (custom) Header EditView Strapi V4
body: <p>I’m trying to add a button and Preview next to the Save and Publish button in EditView, but it’s complicated.
  I already tried putting a plugin (strapi-plugin-preview-button) but it seems that it doesn’t work in version 4+ of Strapi.
  So, I tried to edit in the EditView Header index.js (src/admin/src/content-manager/pages/EditView/Header/index.js), the button even appears, but after doing the build, it disappears.
  I’ve already tried to edit directly in the build, but it also disappears the button after doing the build.
  Do you have any tips, any tutorials to put this Preview button on the page before publishing?</p>
  <p><strong>System Information</strong></p>
  <p><strong>Strapi Version</strong>: 4.1.10</p>
  <p><strong>Operating System</strong>: Linux Ubuntu</p>
  <p><strong>Database</strong>: SQLite3</p>
  <p><strong>Node Version</strong>: 16.0.0</p>
  <p><strong>NPM Version</strong>: 7.10.0</p>
  <p><strong>Yarn Version</strong>: 1.22.18</p>