To cite an Executive Order according to APA 7th edition:
Exec. Order No. xxxxx, 3 C.F.R. Page (Year). URL
Exec. Order No. 13,676, 3 C.F.R. 294 (2014). https://www.govinfo.gov/content/pkg/CFR-2015-title3-vol1/pdf/CFR-2015-title3-vol1-eo13676.pdf
The 3 C.F.R. represents federal executive orders because federal orders are reported in Title 3 of the Code of Federal Regulations. If the executive order is not a Federal executive order, replace the "3 C.F.R." with the code for where the order was reported.
For in-text you will need to use a format such as parenthetical: (Exec. Order No. 13,676, 2014) OR narrative: Executive Order No. 13,676 (2014)
Information found on p.356, 365-366 in APA 7th edition.