openssl encrypt by specifying AES 256 key instead of passphrase

I need to encrypt some data using aes-256-ecb since a backend code expects it as a configuration. I'm able to encrypt using a key which is derived from a passphrase using: openssl enc -p -aes-256-ecb -nosalt -pbkdf2 -base64 -in data-plain.txt -out data-encrypted.txt | sed 's/key=//g' This encrypts using derived key and outputs the key in console. However, I couldn't find how to do it with a generated key, something like: 1. Generate a 256-bit key using: openssl rand -base64 32 > key.data 2. Then use this key during encryption, with something like: openssl enc -p -aes-256-ecb **-key=key.data** -nosalt -pbkdf2 -base64 -in data-plain.txt -out data-encrypted.txt Is this possible?