If this text is coming from any php file the use your text in following way:
__("Your text message");
If this text is coming from any phtml file the use your text in following way:
<?= __("Your text message"); ?>
If this text is coming from any js file the use your text in following way:
require([
'jquery',
'mage/translate'
], function($){
alert($.mage.__('Your text message'));
});
And be sure that your translation string is available in translation csv file.
Hope it will help