I just followed the instructions at https://hacs.xyz/docs/configuration/legacy
After copying over all of the files and generating my GitHub token, I added the following to the bottom of configuration.yaml:
# HACS
hacs:
token:
sidepanel_title: Community
sidepanel_icon: "mdi:alpha-c-box"
release_limit: 5
country:
I just added my personal token from GitHub on the token line and then specified by country with its two-character code on the country line. After restarting Home Assistant, everything worked as it should.