It appears in the same list of contract terms as everything else a parent agrees to when they enter the program:
“Not file an affidavit of intent to homeschool pursuant to section 15-802, subsection B, paragraph 2 or 3.”
Arizona treats these as alternative statuses. A school-age child is accounted for in exactly one way: enrolled in a public school, enrolled in a charter, attending a private school, homeschooling under an affidavit — or holding an ESA contract. The ESA is its own lane, not a funding source you bolt onto homeschooling.