Thanks Hardik i found it already and I tried replacing the header image but didn't seem to work. Don't know what i'm doing wrong. Below is the code. If you know anything please help or point the errors.

<template id="external_layout_standard_chrims" inherit_id="external_layout_standard">

<xpath expr="//div[@class='col-3 mb4']" position="replace">

<div class="col-3 mb4">

<img t-att-src="data:image/jpg;base64,account_analytic_account.invLogo" style="max-height: 45px;" alt="Logo"/>

</div>

</xpath>

</template>

I think you made mistake in: 't-att-src'. see this https://www.odoo.com/es_ES/forum/ayuda-1/question/how-to-rescale-images-on-a-report-pdf-109887

Thanks for the link but that is still unclear to me. My case here is that i declared a custom field in a model and asking the user to upload an image and now i want that image to appear in my qweb report. I have searched a lot and tried a few ways but nothing worked maybe it's because the db is not storing the image i mean when i view the data in the column it shows as empty but then again i can view the image in the ui. I tried using store=True, still no luck! Do you know why is this happening and also tell me how to refer to this image in qweb