How do i get a full url inside a class that extends AbstractHelper using magento 2.4

I have a class that extends AbstractHelper

In this class i make a curl call to an external site. In the payload i need to provide a link to a static css file that resides in my extensions directory.

Experimenting, i have been able to get the required URL in an view->frontend–>templates->index.phtml

<?php
    $xioDefault = $this->getViewFileUrl("xio_OnlinePayment::css/xioDefault.css");
    error_log("(".__LINE__.")".__METHOD__."$xioDefaultn");
?>

the URL i see is something like

http://localhost/static/version1651243933/frontend/Magento/luma/en_US/xio_OnlinePayment/css/xioDefault.css

What i can not figure out (magento noob), is how to get this same URL in my class that extends AbstractHelper that i then can pass to my curl payload.

getViewFileUrl is not something that available in AbstractHelper

Thank you for your help