Content Security Policies (CSP) are a powerful tool to mitigate against Cross Site Scripting (XSS) and related attacks, including card skimmers, session hijacking, clickjacking, and more.
By default, Content Security Policiy is configured in report-only mode, which allows merchants and developers to configure policies to work according to their custom code.
Your browser is not showing a Magento 2 error, it is reporting a CSP policy violation
You can configure your own custom CSP rules by adding a csp_whitelist.xml to a custom module etc folder.
To whitelist the host we have to create a custom module and add the following hosts in the file csp_whitelist.xml layout file
<csp_whitelist xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Csp:etc/csp_whitelist.xsd">
<policies>
<policy id="img-src">
<values>
<value id="blob" type="host">blob:</value>
</values>
</policy>
</policies>
</csp_whitelist>