o.s.boot.SpringApplication               : Application startup failed
...
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Invocation of init method failed; nested exception is org.flywaydb.core.api.FlywayException: Unable to obtain Jdbc connection from DataSource
...
Caused by: org.flywaydb.core.api.FlywayException: Unable to obtain Jdbc connection from DataSource
...
Caused by: org.postgresql.util.PSQLException: FATAL: no pg_hba.conf entry for host "54.xxx.xx.xxx", user "u94bf9vxxxxxx", database "d2mqk0b6xxxxxx", SSL off
...

spring:
    datasource:
        driverClassName: org.postgresql.Driver
        url: ${JDBC_DATABASE_URL}
        username: ${JDBC_DATABASE_USERNAME}
        password: ${JDBC_DATABASE_PASSWORD}
flyway:
    enabled: true
    locations: classpath:db/migrations