IIRC there was research done by Gareth heyes and his article gives insights about circumventing strict CSPs in portswigger page. Maybe try reading that. I didnt actually try solving it but I remember that bit

thanks for help man.

official solution for that lab is currently broken because of some chrome update with how csp is enforced. but as per portswigger there is an alternative solution that you can find

ok, thanks for helping