Linux Layer: Debian Stretch ELF error

[Beeblebrox]

Hello. I setup a Debian/Stretch (amd64) system in a jail using
debootstrap. I've configured it correctly and wanted to see whether
firefox would work. But,

$ /usr/compat/usr/bin/firefox-esr -v
ELF interpreter /lib64/ld-linux-x86-64.so.2 not found, error 2, Abort

Modifying /etc/libmap.conf did not work, neither did some sym-linking.
Is there a simple sloution or am I way over my head?
Regards.

-- 
FreeBSD_amd64_12-Current
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