Well, I should warn you that with the not-so-recent migration of this ProConnect Community forum platform, the Lacerte SDK section hasn't worked for me much.

You will have to add yourself to the subforum, as I recall. The list of posts there has been blank for me ever since the migration. It might display for you, though.

https://proconnect.intuit.com/community/lacerte-sdk-group/gp-p/501

In the top here, under Community, then User Groups, should get you there. I use this google search:

site:https://proconnect.intuit.com/community/ lacerte sdk

Because this forum has no real functional search.

There is SDK here:

https://proconnect.intuit.com/community/permissions/help/lacerte-software-developer-s-kit/00/102313

and here, but you would need to log in and be "developer" using your Intuit ID/log in:

https://developer.intuit.com/app/developer/lacerte-sdk/docs/lacerte-get-started

And of course, the reference material, similar to the access points, are not well maintained. Things change, without the related references changing. For instance:

https://proconnect.intuit.com/community/lacerte-sdk-group/sql-to-join-efstatus-to-client-info/gpm-p/...

https://proconnect.intuit.com/community/lacerte-sdk-group/insert-data-into-detail-table/gpm-p/40717

https://proconnect.intuit.com/community/lacerte-sdk-group/table-of-codes/gpm-p/970

And in case the SDK links are not as current, here is one from that recent posting:

https://intuit.app.box.com/s/b7fp0bgz6kdof8k2cl0w8omrv5blwq4p

If I am understanding your issue, you want Client Number, not GUID. Apps have GUID.

Good luck.