Request Ajax WordPress for an external API

Hi, I would like to know how I could make an ajax request via HTTP for an external REST API? Using wp_remote_post ($ url, $ args), how to perform the form call and where to fit the function, how to perform the field processing, etc., would anyone know? Ex:

FORM:


and in the functions.php i put the following code, however i do not know how to call, and if it's really in functions.php:

    $ email,
& # 39; full name & # 39; => $ full name,
& # 39; phone & # 39; => $ phone,
& # 39; password & # 39; => $ password,
)

$ args = array (
& # 39; method & # 39; => & # 39; POST & # 39 ;,
& # 39; timeout & # 39; => 45,
& # 39; body & # 39; => $ body,
)

$ response = wp_remote_post ($ url, $ args);

}
?>