The project uses gradle 5.4.1 (see Dockerfile FROM) and you just need to let Intelij know where to get the correct version of gradle. One way is to create a file called gradle/wrapper/gradle-wrapper.properties
with the following content:
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-bin.zip
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
Also make sure jdk/jvm 1.8 is selected in the project
and
If all set correct, you can see Intelij compile and index the project: