Driver comes from http://foo2hbpl.rkkda.com/ :
wget -O foo2zjs.tar.gz http://foo2zjs.rkkda.com/foo2zjs.tar.gz
tar xf foo2zjs.tar.gz
cd foo2zjs && make
sudo make install
Settings->Printers->(Unlock)->Add
Select the printer (Assuming network connection is OK)
Printer->Settings->Details->Select From Database
Select the Dell C1765 - and start printing :)
In later Fedora versions you can simply do
sudo dnf install foo2hbpl
and that'll get youC1765
support that works. I've just tested this in Fedora 38 at least.