Get Current date time in UTC using XSLT version 1

Question

I am using

<xsl:with-param name="value" select="date:date-time()"/>
xmlns:date="http://exslt.org/dates-and-times" extension-element-prefixes="date" date:doc="http://www.exslt.org/date" version="1.0">

I am getting this output

"event_datetime_utc":"2020-11-22T12:25:32+05:1800000"

How to get Z (ZULU) at end without the +05:1800000 offset?