IntelliJ IDEA does not read user environment variables - intellij-idea

Question

I have a Spring Boot 2.x application that I run within IDEA using the usual Run/Debug Configuration for Spring Boot. This works fine, but now I have to use some environment variables, and I'm placing them in the Environment variables field (from the Configuration tab)...but so far it is not picking up those values:
04-15-2021 11:08:13,233 |- WARN in n.g.e.SimpleDataFetcherExceptionHandler:25 [http-nio-9580-exec-1] - Exception while fetching data (/endpoint) : Could not open JDBC Connection for transaction; nested exception is java.lang.RuntimeException: Driver oracle.jdbc.OracleDriver claims to not accept jdbcUrl, override_value_here
org.springframework.transaction.CannotCreateTransactionException: Could not open JDBC Connection for transaction; nested exception is java.lang.RuntimeException: Driver oracle.jdbc.OracleDriver claims to not accept jdbcUrl, override_value_here
at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:309)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.startTransaction(AbstractPlatformTransactionManager.java:400)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:373)
at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:595)
It's basically using the default (useless in purpose) values I have in application.yml:
spring:
...
datasource:
driver-class-name: oracle.jdbc.OracleDriver
password: ${DATASOURCE_PASSWORD:override_value_here}
url: ${DATASOURCE_URL:override_value_here}
username: ${DATASOURCE_USERNAME:override_value_here}
What am I missing in the IDE configuration to make this work? I'm using IntelliJ IDEA 2020.3.3 (Ultimate Edition) with Runtime version: 11.0.10+8-b1145.96 amd64 under Windows 10 10.0.
By the way, this is currently working if I run the application via Gradle because it's integrated with a .env file that holds the values. If there is a way to make IntelliJ IDEA read that file I would really like to know!