Hi there!
Thanks for contacting us.
I have checked your system information and the upload max filesize is low there: https://prnt.sc/3Qn8IjceTnyP
This is increased in the php settings on your hosting.
Parameters: upload_max_filesize and post_max_size.
If you are facing difficulty to increase them, kindly ask your hosting support.
However, the following doc may help:
https://www.itoctopus.com/how-to-increase-the-maximum-allowed-size-of-uploaded-files-in-joomlas-media-manager
Kindly check them also according to the SP Page Builder Pro technical requirements and PHP configurations:
https://prnt.sc/lgtZ6dG_NAqM
https://www.joomshaper.com/documentation/sp-page-builder/sp-page-builder-4/technical-requirements
Best Regards