I’ve seen numbers reported between 8 million and 12 million, with variation leaning high or low by R or D bias, but even 8 million is not far from what I said. Here’s a government source, although this was written before the end of his term:

https://homeland.house.gov/2024/05/22/startling-stats-factsheet-biden-administration-on-track-to-reach-10-million-encounters-nationwide-before-end-of-fiscal-year/