This is probably not supported by the HTTPCaller at the moment. (The certificate part.) I believe you can do this in Python using the PythonCaller but I have no working example.

thank you Niels! I'll have a look into Python libraries. In that past, I created a python script for a JWT token. There seems to be a PyJKS Library as well and maybe combine it with Fiddler to find out how the certicate is passed to the SOAP request.

I believe that the HTTPCaller is using the Windows keystore, so if you can import the necessary certificate(s) there, it should work.

SoapUI does not use the Windows keystore, which is why the configuration is different there.

Thank you David. In fact, my first question was to get the certificates so I could install them. We are back at square 1, it seams.

You'll probably have to contact the client and explain that you need the certificates on a format that you can install into the Windows certificate keystore. Such certificates can e.g. have the extension .p12 or .pfx, although some other formats are possible. Sometimes you'll also need to have a password for the certificate.

yes, I found the documentation on the platform of the API on how to export (create) the *.p12 file. A password is required indeed.