URL-encode according to RFC 3986
rawurlencode ( string $str ) : string
The URL to be encoded.
Returns a string in which all non-alphanumeric characters except -_.~ have been replaced with a percent (%) sign followed by two hex digits. This is the encoding described in RFC 3986 for protecting literal characters from being interpreted as special URL delimiters, and for protecting URLs from being mangled by transmission media with character conversions (like some email systems).
<a href="https://domain.com/path?var=encode%20non-alphanumeric">encode non-alphanumeric</a>