Yes – the Oracle client software is free for development, testing, and production use. You only pay for database server licenses.
If sqlplus is not recognized, your Path is wrong. Revisit Step 5. Download Oracle Client 19c For Windows
: Between 430 MB and 1.6 GB, depending on the installation type. Yes – the Oracle client software is free
: You must download both ZIP files and extract them into the same folder before running the installer. Otherwise, the installer will ask for the second disk. Download Oracle Client 19c For Windows