As addition to what I wrote 2 years ago:
if you are installing on Debian with a Debian provided package, install the source with
apt source php8.2
Then you have to set ORACLE_HOME like that:
ORACLE_HOME=/usr/lib/oracle/19.6
export ORACLE_HOME
before running ./configure.
After that, I had to add the include directory
-I/usr/include/oracle/19.6/client64/
into the Makefile to successfully build the module.