Cannot configure Gitlab integration in IntelliJ, authentication fails

I'm trying to integrate my gitlab account into my IntelliJ IDE. 

For this, I've created an access token within my gitlab account. 

If I then run: 

curl "https://repo.base.com/api/v4/version" --header "PRIVATE-TOKEN: {secret}" 

I successfully get a proper JSON response. 

When attempting to login within the IDE and the https://repo.base.com base URL and the same {secret}, by specifying them under Settings > Versioning > Gitlab, and the clicking on “Login”, I get the following response: 

HTTP Request Request GET https://repo.base.com/api/v4/version failed with status code 401 and response body: {„message“:“401 Unauthorized“} 

What's the problem ?