Change You have selected the on the checkout page

my-pmpro-translate-text.php

<?php // Do not copy this line
/**
 * This recipe will change the text on our checkout page. 
 * 
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */
 
 add_filter( 'gettext', 'change_my_text_example', 20, 3 );
/**
 * @link http://codex.wordpress.org/Plugin_API/Filter_Reference/gettext
 */
function change_my_text_example( $translated_text, $text, $domain ) {  
        switch ( $translated_text ) {
       
			case 'You have selected the %s membership level.' : // This is what we want to change
                $translated_text = __( 'Du hast die Mitgliedsstufe %s ausgewählt.', 'paid-memberships-pro' );// this is our change
                break;	
         
        }
    return $translated_text;
}