Cant update Toolbox behind proxy

I'm behind corporate proxy and at first I was getting errors like

Unable to download feed from https://toolbox-internal-feed.labs.intellij.net/feeds/v1/internal-feed.feed.xz.signed: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

So I added certificate to keystore and set _JAVA_OPTIONS. But after that I'm getting errors like

Unable to download feed from https://download.jetbrains.com/toolbox/feeds/v1/thirdparty-feed.feed.xz.signed: Authorization required

But proxy login and password are set in Toolbox settings. What can I do about it?