Hackson Santos da Silva you might find this useful: https://documentation.sas.com/doc/en/statug/15.1/statug_mixed_examples01.htm

Although you will need to modify the code for your specific design.

John

In attachment an example for a slip-plot design using SAS.

see also:

https://www.studocu.com/row/document/government-college-university-lahore/design-analysis-and-algorithms/chapter-19-split-plot-designs/56262892

or:

https://docplayer.net/21029884-Chapter-19-split-plot-designs.html