For Spring Boot 2.1.1 straight from Spring Initialzr:
Default with devtools is http://127.0.0.1:8080/h2-console/
Without devtools - you need to set it in properties: spring.h2.console.enabled=true spring.h2.console.path=/h2-console
Once you get there - set JDBC URL: jdbc:h2:mem:testdb (The default one will not work)