How to write value from cookie to dynamic form?

Question

JavaScript

Good day everyone. There is a dynamic form in php , Region ==> City, there are also region and city key pairs recorded in coockie

{"city":{"id":7779062,"name_ru":"\u0423\u0441\u0441\u0443\u0440\u0438\u0439\u0441\u043a","name_en":""
},
"region":{"id":"226","name_ru":"\u041f\u0440\u0438\u043c\u043e\u0440\u0441\u043a\u0438\u0439 \u043a
\u0440\u0430\u0439","name_en":""}}

Tell me how to write the region and city into a dynamic form when loading a page from cookies?

Answer 1

From cookies? The page is not loaded from cookies, it can be generated with cookies!
PHP: use $_COOKIE cookie variable when serving a page.
JS: document.cookie variable
Or do you need a hint on how exactly to insert this information into the object?