browser.platform

This value is intended to be taken from the UA client hints API (navigator.userAgentData.platform). If unavailable, the legacy navigator.platform API SHOULD NOT be used instead and this attribute SHOULD be left unset in order for the values to be consistent. The list of possible values is defined in the W3C User-Agent Client Hints specification. Note that some (but not all) of these values can overlap with values in the os.type and os.name attributes. However, for consistency, the values in the browser.platform attribute should capture the exact value that the user agent provides.