I did some testing and all the files with .feature as an extention will be recognized by intellij as a cucumber feature file. This will be so when I do New -> File -> Gherkin feature file or just creating a new file and giving it the extension .feature.
There could be two possibilities:
- either you installed the plugin but did not yet restart IntelliJ. Fix this by restarting intellij
- or the plugin is not active in intellij, check this by going to preferences, plugins and make sure the checkbox at Cucumber plugin is checked.
Outside of this I have no clue. Let us know what worked?