Issue with nanoid

[parkerdevs]

It looks like the nanoid function is generating a value that is no longer compatible with @SimpleWebAuthn startRegistration() function. From what I can tell, the value options.user.id should be base64url-encoded UTF-8 bytes when passed into startRegistration().

SimpleWebAuthn - Custom User IDs

[ferdinandlist]

I also ran into this and created a workaround in a copy of handleFormSubmit:

id: btoa(config?.generateUserId?.() || nanoid());

I guess actually supplying a custom generateUserId using btoa() in the same manner would also work as a temporary workaround.

(Just leaving this here in case someone gets stuck looking for a fix)