chromium/third_party/blink/web_tests/http/tests/inspector-protocol/resources/iframe-request-trust-token.html

<iframe src="https://issuer.example" privatetoken="{&#x22;version&#x22; &#x3a; 1 &#x2c; &#x22;operation&#x22;: &#x22;send-redemption-record&#x22;, &#x22;issuers&#x22;: [&#x22;https://issuer.example&#x22;] }"></iframe>