No access to admin page after PiHole installation

As requested, here the output of "uname -m":

x86_64

And the output of "dpkg --print-architecture":

i386

Following the exchanges on another post, further info can be provided.

Output of "strings /usr/bin/pihole-FTL | head":

/lib64/ld-linux-x86-64.so.2

Output of "dpkg -S ld-linux-x86-64.so.2":

dpkg-query: no path found matching pattern *ld-linux-x86-64.so.2*

Output of "stat ld-linux-x86-64.so.2":

stat: cannot stat 'ld-linux-x86-64.so.2': No such file or directory

Output of "whereis ld-linux-x86-64.so.2":

ld-linux-x86-64.so.2:

Thus, from above steps, to me it looks like a library is missing...

However, when firing the command "sudo apt-get install libc6" as suggested with another post, I'm getting the following output:

Reading package lists... Done
Building dependency tree
Reading state information... Done
libc6 is already the newest version (2.24-11+deb9u1).
0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.