Hi there!
Sorry for your issue.
Please use the following code in your custom CSS:
#sppb-addon-1671686649318 .form-builder-checkbox-item label::before {
margin-left: -20px;
}
.form-builder-checkbox-content label {
margin-left: 50px;
}
Hope this will give you better view there!
Note: Path towards custom CSS(Joomla 4): System>Site Templates Styles> Click on your current default template name then choose Template Options. Then find custom CSS within the custom code.
https://prnt.sc/5mBuSRh907N3
https://prnt.sc/ooiq-lkMEXr_
https://prnt.sc/nunlX-f5AhK1
Best Regards