adding your label into admin global translation

/opt/lampp/htdocs/ksquare-backup/app/Resources/translations/default/AdminGlobal.xlf

if you are using the following translation format, just follow the below steps accordingly

            <div class="col-sm text-center">

              <p class="text-muted mb-0"><strong>{{ 'Paid Amt'|trans({}, 'Admin.Global') }}</strong></p>

              <strong id="orderPaymentPaid">{{ orderPaymentPaidAmt }}</strong>

            </div>

id is the md5 encoded string, put your source "Quantity" into below md5hash generator

https://www.md5hashgenerator.com/