Create a spot-on reference in APA 7 and 6
Basic rules
APA Style (7th edition) provides explicit instructions for referencing the laws of the United States only. For citing a US law in a list of references, APA requires to indicate the title of the law, the chapter and section numbers, the date of publication in the appropriate source or, should it be missing, the date when the law was last amended or the date when it was enacted.
For citing laws which are foreign to the US (i.e. laws of Italy, France, Germany, etc.), the standard requires following the rules set out in The Bluebook, combining them with the general principles of APA. The Bluebook provides templates for a number of foreign jurisdictions, generally requiring a reference to a foreing law or act to include its title and type, number, date of publication in the appropriate source or, should it be missing, date when it was last amended or date when it was enacted.
Next, in both cases, the data pertaining to the appropriate source where the law was published are provided (the address of the website, data of the newspaper, etc.).
However, while the APA Manual recommends using The Bluebook for foreign laws, it should be borne in mind that such reccommendations are designed for the US users. As a result, often, local institutions in other countries recommend using local or combined standards for legal references (see examples of such references below).
Examples of references
According to the rules of the APA Manual (U.S.)
Americans With Disabilities Act of 1990, 42 U.S.C. § 12101 et seq. (1990). https://www.ada.gov/pubs/adastatute08.htm
Taking into account the provisions of The Bluebook
Copyright Act No. 63 (2017) (Austl.). https://www.legislation.gov.au/Details/C2017C00180
According to local recommendations
As recommended by James Cook University for Australian legislation:
Anti‑Money Laundering and Counter‑Terrorism Financing Act 2006 (Cth) pt 3.
As recommended by Université de Montréal for Canadian legislation:
Éditeur officiel du Québec. (2002, 14 juin). Projet de loi no 90 : loi modifiant le Code des professions et d’autres dispositions législatives dans le domaine de la santé. http://www.ooaq.qc.ca/ordre/lois-reglements/doc-lois/loi-90.pdf