Here's a simple QWeb report snippet that generates ZPL code to print a contact's name and phone number on a Zebra printer:
<t t-name="your_module.zpl_contact_label">

  <t t-foreach="docs" t-as="doc">

    <![CDATA[

^XA

^CF0,30

^FO50,50^FDName: <t t-esc="doc.name"/ >^FS

^FO50,100^FDPhone: <t t-esc="doc.phone"/ >^FS

^XZ

    ]]>

  </t>

</t>

Replace your_module.zpl_contact_label with your actual report name.

Pass the contact record(s) as docs when rendering the report.

This will print the contact's name and phone at positions (50,50) and (50,100) on the label.

You can adjust the font size (^CF0,30) and coordinates (^FOx,y) as needed.

i hope it is help full