Dotenv multiline variables
Did you try reading the documentation?
Multi-line values
If you need multiline variables, for example private keys, you can double quote strings and use the \n character for newlines:
PRIVATE_KEY="-----BEGIN RSA PRIVATE KEY-----\nHkVN9…\n-----END DSA PRIVATE KEY-----\n"
From the documentation Brian posted above:
Alternatively, multi-line values with line breaks are now supported for quoted values.
So the solution you sketched in your question is legit now!