Thanks for your questions, David. My initial B2 Visa expired May 16th 2020, I filed and paid for extension of Visa on May 6th 2020 with I-539 form. About biometrics, They wrote On January 8, 2021, and asked if no letter arrives by Feb 7th 2021 I should contact a certain office to which there is a link on the form. thanks for any insights! Bless you!