When running Big Sur, addons are not installed by default. These addons require manual installation steps.
In order to install addons, you need to start the Anka VM with the -uv options:
❯ anka start -uv 10.15.7
+-----------------------+--------------------------------------+
| uuid | c0847bc9-5d2d-4dbc-ba6a-240f7ff08032 |
+-----------------------+--------------------------------------+
| name | 10.15.6 (base:port-forward-22) |
+-----------------------+--------------------------------------+
. . .
❯ anka run -n 10.15.7 bash -c "ls -alht /Volumes/"
total 0
drwxr-xr-x 4 root wheel 128B Nov 9 14:16 .
lrwxr-xr-x 1 root wheel 1B Nov 9 14:15 Macintosh HD -> /
drwxr-xr-x@ 4 anka staff 136B Nov 6 12:51 Anka Guest Addons 2.2.3(118.6755654)
drwxr-xr-x 22 root admin 704B Sep 25 11:48 ..
You can now go into the VM and manually install addons using the installer package inside of the Anka Guest Addons mounted disk.