Hello @shahar klamka,
We regret to inform you that it is not possible to achieve your desired outcome using the theme options available for grouped and affiliate/external products, the Ajax Add to Cart option only works for Simple and Variable products https://prnt.sc/hxpDU1FRCQWj . You may wish to explore third-party plugins that may better meet your requirements, but please note that this is done at your own risk.
If you would like to request this feature, please post your request on our Taskboard at https://www.8theme.com/taskboard/. If it receives enough votes from other customers, our development team will consider adding it to one of our future updates.
We thank you for your understanding and look forward to your continued support.
Best Regards,
8Theme’s Team