With IDN, you can offer your products in the language of the country you are targeting and also respect the special characters and accents (é, ê, è, ë..). You can use and combine characters, numbers and symbols of more than 350 different languages.
Whatever the extension or the registrar, the domains containing non-ASCII characters must be converted. This conversion is internal, and all browsers do it automatically, so your visitors will of course be able to use the format with special characters to visit your site.
A domain containing special characters (non-ASCII) is normalised with the addition of the ACE prefix (ASCII Compatible Encoding) presented in the form xn-- and change the rest of the domain. This is the address containing the prefix that will be used for your DNS records. A converter is available here.
OVH immediately detects the language in which you want to register. No need to install a plug-in... everything is done automatically.