Could you please let us know what issue or error you are encountering when trying to import the layout? If possible, please share a screenshot or screen recording of the import process and the issue you are experiencing so we can investigate it further.
Regarding the SP Page Builder integration button, please note that the integration is disabled by default. If you need to use SP Page Builder with Joomla articles, you will need to enable the integration from the relevant SP Page Builder settings.
Once enabled, the integration option should remain available unless it is manually disabled or affected by another configuration or extension conflict.