Can not locate and click on "UPDATE BTN"

Test running on protractor. Having problem with locating element.

HTML CODE

I was locating by :

 var update = element(by.xpath('//span[@class="mat-button-wrapper"][text()="Update"]'));
            browser.executeScript("arguments[0].click();", update);

Did not work ,added time still unable to locate element.Can you help me pls.Thanks