how can a plugin return an error message on activation?

I use code similar to this to check for the minimum requirements for a plugin:

if (is_admin()) {
// check for required versions of WP and PHP
    $min_wp  = '4.9.6';
    $min_php = '7.2';
    if (!check_requirements($min_wp, $min_php)) {
        add_action('admin_init', 'my_disable_plugin');
        add_action('admin_notices', 'my_show_notice_disabled_plugin');
        add_action('network_admin_init', 'my_disable_plugin');
        add_action('network_admin_notices', 'my_show_notice_disabled_plugin');
function check_requirements($min_wp, $min_php) {
   // see this for how to check requirements 
   // set $requirements_met true if OK, false if not OK
return $requirements_met;

function my_disable_plugin() {
   // disable the plugin 
function my_show_notice_diabled_plugin() {
   // admin notice that plugin disabled
function my_deregister() {
   // de-register the plugin

So if on the admin page, the plugin minimum requirements are checked. If that fails, the plugin is disabled and de-registered, and the admin notices displayed with the alert.