I tried to add methods from documentation but I did not help. I also tried to rewrite it to SOAP::Lite and use methods that I mentioned but no success. The only way I can authenticate is when I put username and password in URL like this: https://username:password@example.com. But in this case the password appears unencrypted in server logs. There is digest authentication enabled on server but should not these methods handle it automatically? This is the response header I get from server:

HTTP/1.1 401 Unauthorized
Date: Tue, 27 Mar 2018 13:23:32 GMT
Server: Microsoft-IIS/7.5
WWW-Authenticate: Digest qop="auth",algorithm=MD5-sess,nonce="+Upgrade
+d+v10b38d21e7aaf1202a77846a2fe9d2bd901d0c2cdcec5d30156158f0a13e8aeec6
+774eb0a8e77f7baeeac127503c4b3e86a776f449098b7a4",charset=utf-8,realm=
+"Digest"
WWW-Authenticate: Negotiate
WWW-Authenticate: NTLM
WWW-Authenticate: Basic realm="example.com"
Content-Length: 1293
Content-Type: text/html
Client-Date: Tue, 27 Mar 2018 13:23:32 GMT
Client-Peer: xxx.xxx.xxx.xxx:port
Client-Response-Num: 1
Client-SSL-Cert-Issuer: something
Client-SSL-Cert-Subject: something
Client-SSL-Cipher: ECDHE-RSA-AES256-SHA
Client-SSL-Socket-Class: IO::Socket::SSL
Title: 401 - Unauthorized: Access is denied due to invalid credentials
+.
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