Help:URL
Writing URLs in wikitext
A complete URL beginning with https:// or http:// is usually recognised as an external link. For a labelled link, put the URL and label inside one square-bracket pair, separated by a space:
[https://www.frontier.co.uk/ Frontier Developments]
If you omit the label, the wiki may display a numbered link. Use a short, descriptive label when the destination matters to the reader.
Characters that need care
Spaces in a URL are not valid as literal spaces; use the encoding required by that service, commonly %20, or use the canonical URL copied from the destination. In query strings, an ampersand separates parameters. In wikitext, a raw ampersand may be interpreted as the start of a character entity, so write it as & when necessary, for example https://example.org/?a=1&b=2. Preview to confirm the resulting link.
Safe, useful links
Check that the URL works and leads to the cited material. Prefer secure HTTPS addresses where the source provides them. Do not disguise a destination, use a URL shortener to obscure it, or include tracking fragments unless they are needed. For internal links, use wiki-link syntax such as Page title; see Help:Link.