How to make it accessible for other roles except administrators?

I just pushed an update version 1.2 that allows you to modify the capabilities a user needs to be able to view the menu item and admin screen. As an example you could create a new functionality plugin by adding a file “ecn-change-cap.php” in your plugins folder with the following:

<?php
/*
Plugin Name: Event Calendar Newsletter Change Cap
Description: Allow other users to access the Event Calendar Newsletter screen
Version: 1.0
Author: Brian Hogg
Author URI: https://brianhogg.com
License: GPL2
*/

function ecn_change_cap( $cap ) {
	return 'publish_posts';
}

add_filter( 'ecn_admin_capability', 'ecn_change_cap' );

And this would change the capability required from ‘add_users’ to ‘publish_posts’ which by default will allow users with the Author, Editor and Admin roles to use it, but not Contributors and Subscribers:

https://codex.www.ads-software.com/Roles_and_Capabilities

Thanks!

Thanks Brian,
you said you made an update version 1.2, but I cannot see it online, it’s still 1.1

There was an issue with the version update, it’s now been fixed.

Thanks!
Brian