@babel/plugin-transform-dotall-regex enables support for the s (dotAll) flag in regular expressions within JavaScript code. This flag allows the dot (.) metacharacter to match newline characters, offering more versatile pattern matching. This Babel plugin transforms regular expressions using the s flag into equivalent expressions compatible with older JavaScript environments that don't natively support it. By using this plugin, developers can leverage the dotAll flag in their code while maintaining broader browser compatibility.