My solution is below:

1. First, install plugin https://plugins.jetbrains.com/plugin/14004-protocol-buffers

2. needs some extra effort to parse Google and validate imports: clone these two repo you need in your project

   • https://github.com/googleapis/googleapis

   • https://github.com/bufbuild/protoc-gen-validate

3. manually add the import path in the settings (Settings -> Languages&Frameworks -> Protocol Buffers)

PS: It's so dull IDEA still supports protocol not very well now.