Hi Salesforce Pros,  

We are preparing to turn on Salesforce Authenticator, in classic.  In most cases, our users are able to use the SF Authenticator App but there are instances where we will need to use a token. I know the token needs to be U2F but does it need to be a USB token but does the system allow for tokens that do not connect via USB?   If so where would I go to import the token id number for a user?