URLs with parameters containing special characters (including spaces) needs to be encoded using so-called percent encoding and I suspect the HTTPCaller tries to do it for you.
You can also encode the parameter values manually using the TextEncoder transformer, that way you'll have more control over the final URL.
Hi @j4, as you say, I believe Ñ should be encoded to %C3%91, rather than %D1. It could be a defect of the HTTPCaller. Hope someone from Safe will check this.
As a workaround in the interim, as @david_r mentioned, you can use the TextEncoder to encode the parameters and then construct desired URL string containing the parameters, in the URL parameter field.
URLs with parameters containing special characters (including spaces) needs to be encoded using so-called percent encoding and I suspect the HTTPCaller tries to do it for you.
You can also encode the parameter values manually using the TextEncoder transformer, that way you'll have more control over the final URL.