SOAP client could not be loaded. WSDL Operation nodes could not be created/updated.

Problem/Motivation

When trying to upload a WSDL in the UI from a URL, I get the following error:
Error: SOAP client could not be loaded. WSDL Operation nodes could not be created/updated.

Is this perhaps caused by not having the dependency module "wsclient" installed? However this module is not supported by D9, so not sure how to resolve this...

Steps to reproduce

• Default installation of Apigee Developer Portal Kickstart (D9)
• Install WSDL Docs module
• Add Content > SOAP Service
• Use a sample WSDL file URL as source, such as http://www.thomas-bayer.com/axis2/services/BLZService?wsdl

Would appreciate any help here. Thanks.