HTMLViewer not allowing cookies?

I have a webapp which is initiating a payment process over a httpsocket and when it is getting back an URL then it tries to open it in an iFrame. The third party payment terminal (SIX Saferpay) is making use of cookies.

This works well with all standard-browsers, but when I try to run this webapp in a HTMLViewer of a desktop application, then it fails with a saferpay message that cookies are not enabled.

Is there a way to enable cookie storage for a desktop HTMLViewer?

What exactly is the situation with HTMLViewer (desktop) and cookies?

When one opens a URL in the HTMLViewer which depends on cookies, what is happening then? Is this supposed to work out-of-the-box or is this one of its limitations?

Did you check out this? https://www.monkeybreadsoftware.net/example-cocoacontrols-htmlviewermac-maccookies.shtml

Yes, but at the moment I don’t see how it would help in my case.

My webapp does not directly make use of cookies, but it seems the saferpay webapp (aka “terminal”), which I am opening in an iFrame, does. At least its error message is a hint in that direction.

Now I would need to know whether HtmlViewer is handling cookies like a standard browser,or not at all.

HTMLViewer may accept cookies, but does not store them permanently.
So you can use plugin classes to query cookies and restore them later.