tl;dr: - chrome hides OPTIONS requests in dev tools - chrome disallows cross-origin requests to extensions permission urls [1] [1] https://www.chromium.or

tl;dr: - chrome hides OPTIONS requests in dev tools - chrome disallows cross-origin requests to extensions permission urls [1] [1] https://www.chromium.org/Home/chromium-security/extension-content-script-fetches/ https://www.chromium.org/Home/chromium-security/extension-co... "extension content scripts have traditionally been able to fetch cross-origin data from any origins listed in their extension's permissions, regardless of the origin that the content script is running within. As part of a broader Extension Manifest V3 effort to improve extension security, privacy, and performance, these cross-origin requests in content scripts will soon be disallowed."