I experienced exactly the same issue when I spun up the Kreativa quickstart (kreativa_quickstart_j4_v1.0.2), and can confirm that Hannah is 100% correct!
Renaming the file [root]/administrator/components/com_sppagebuilder/models/appConfig.php
to
[root]/administrator/components/com_sppagebuilder/models/appconfig.php WORKS.
I'm developing on mac too, so find it hard to understand how you could have done so without experiencing the same 500 error, @Toufiq.
Please, update your quickstart with the above changes to fix this issue.
Thanks!