$ yum info php-oci8
...
: The extension is linked with Oracle client libraries 19.6
: (Oracle Instant Client). For details, see Oracle's note
: "Oracle Client / Server Interoperability Support" (ID 207303.1).
:
: You must install libclntsh.so.19.1 to use this package, provided
: in the database installation, or in the free Oracle Instant Client
: available from Oracle.
...