Connection to ING iDEAL Basic – problem

hello

currently I am trying to connect ING iDeal service using Pronamic Pay plugin. I am using wordpress/woocommerce.

Is it required to have paid license – or basic function of ‘ING iDEAL’ option should works?

I am unable to perform mandatory Testcase 2-7;
test payment redirects to white screen https://idealtest.secure-ing.com/ideal/mpiPayStart.do
(https://larido.pl/gallery/2021-04-07-pronamicpay/1.jpg)

Connection between WordPress and ING iDeal Basic looks to be working – but there are some problems to perform mandatory test phase.(https://larido.pl/gallery/2021-04-07-pronamicpay/2.jpg)

Connection between WordPress and ING has been setup as specified here:
https://www.pronamic.nl/support/pronamic-ideal-koppelen-aan-ing-ideal-basic/
https://translate.google.com/translate?sl=nl&tl=en&u=https%3a%2f%2fwww.pronamic.nl%2fsupport%2fpronamic-ideal-koppelen-aan-ing-ideal-basic%2f

But it was possible to perform only the Testcase1 (https://larido.pl/gallery/2021-04-07-pronamicpay/4.jpg)(so I think connection was working)
One transaction only sucessed..
After that – it is not possible to perform next mandatory tests (Testcases 2-7).
Redirection from Wordpres to ING works (https://larido.pl/gallery/2021-04-07-pronamicpay/3.jpg)- but after selecting V3 ING and click ‘betalen’ it redirects to … white screen:
https://idealtest.secure-ing.com/ideal/mpiPayStart.do

Are any suggestions from authors of Pronamic Pay?
Is it required to have licence or basic function of ‘ING iDEAL’ option should works?

Best Regards
—
Larido

The page I need help with: [log in to see the link]