Add a 'Show Password' on Paid Memberships Pro login page.

show-password-login-toggle.php

<?php
/**
 * Add a checkbox to frontend login page of WordPress to toggle the password text visible/hidden.
 *
 * Add this code to a custom plugin or Code Snippets Add On: https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 * Source: https://www.w3schools.com/howto/howto_js_toggle_password.asp
 */

function my_pmpro_show_password_login_toggle( $items, $args ) {

    $items .= '<input type="checkbox" onclick="my_show_password()"> Show Password';
    
    ?>
        <script>
            function my_show_password() {
            var x = document.getElementById("user_pass");
            if (x.type === "password") {
                x.type = "text";
            } else {
                x.type = "password";
            }
            }
        </script>
    <?php

    return $items;

}
add_filter( 'login_form_middle', 'my_pmpro_show_password_login_toggle', 10, 2 );

To match the font settings of "remember me" add a label tag to the snippet:
Hello,

$items .= '<label><input type="checkbox" onclick="my_show_password()"> Show Password</label>';