I can reproduce on meta and locally as well. From a quick look, it doesn’t look related to passkeys but rather a similar regression to the one @david fixed the last time.
Before pressing the “Authenticate with Security Key” button, I see JS errors:
Uncaught Error: Could not find module `discourse/loader-shims` imported from `(require)`
at missingModule (loader.js:247:1)
at findModule (loader.js:258:1)
at requireModule (loader.js:24:1)
at eval (i18n:1:1)
at en.js:1:1
and
loader.js:247 Uncaught Error: Could not find module `discourse/lib/ajax` imported from `discourse/lib/webauthn`
at missingModule (loader.js:247:1)
at findModule (loader.js:258:1)
at Module.findDeps (loader.js:168:1)
at findModule (loader.js:262:1)
at Module.findDeps (loader.js:168:1)
at findModule (loader.js:262:1)
at requireModule (loader.js:24:1)
at eval (bootstrap:3:3)
at eval (bootstrap:4:3)
at bootstrap.js:1:1
Can you have a look, @david?