Sir this is the phython code :
from odoo import api, fields, models, _

class PurchaseOrderLine(models.Model):
_inherit = "purchase.order.line"

image_128 = fields.Image(string="Image")

@api.onchange('product_id')
def onchange_purchase_product_image(self):
for product in self:
product.image_128 = product.product_id.image_128

This is the xml code :
<?xml version="1.0" encoding="utf-8"?>
<odoo>
<template id="purchase_report_inherit_id" inherit_id="purchase.report_purchaseorder_document">
<xpath expr="//table[1]/thead/tr[1]/th[1]" position="after">
<th class="text-right">Image</th>
</xpath>
<xpath expr="//table[1]/tbody/t[2]/tr[1]/t[1]/td[1]" position="after">
<td class="text-right">
<img t-if="line.image_128" t-att-src="'data:image/png;base64,%s' % to_text(line.image_128)"
style="width: 150px;height: 150px"/>
</td>
</xpath>
</template>

<template id="purchase_quotation_report_inherit_id" inherit_id="purchase.report_purchasequotation_document">
<xpath expr="//table[1]/thead/tr[1]/th[1]" position="after">
<th class="text-right">Image</th>
</xpath>
<xpath expr="//table[1]/tbody/t[1]/tr[1]/t[1]/td[1]" position="after">
<td class="text-right">
<img t-if="order_line.image_128" t-att-src="'data:image/png;base64,%s' % to_text(order_line.image_128)"
style="width: 150px;height: 150px"/>
</td>
</xpath>
</template>

</odoo>

Can you please tell me what changes i should make here so i can achieve this

add your td inside this if condition:

<t t-if="any(line.image_128 for line in o.order_line)">
</t>

Thank you so much sir it worked perfectly