First, execute ./build.sh (or make build). You will need dockerx installed (included in Docker Desktop).
The Docker image should be built once. You also may change NLS_LANG property in common.sh.
After the Docker image has been built, edit newly created file sqlplus.config and set parameter LOCAL_TNS_ADMIN.
Value of this parameter should point to directory containing configuration files of Oracle InstantClient.
Example:
LOCAL_TNS_ADMIN=/Users/me/apps/oracle/instantclient/network/admin.
Switch to your patch's directory and execute <sqlpdock_path>/run.sh <user@schema>.
Then you need to enter a password and may start to execute your SQL scripts.
To exit the program use exit command.
For your convenience, you may register alias: alias sqlpdock='<sqlpdock_path>/run.sh'.
In that case, the execution command becomes more compact: sqlpdock <user@schema>.