updates

src/core/Rt.js

@@ -171,9 +171,15 @@ export class Rt {
 				if (reqOpts.vars instanceof FormData) {
 
 					for (const [key, value] of reqOpts.vars.entries()) {
+						
+						if (key.endsWith('[]')) {
+							fdata.append(key, value);
+						}
+						else {
 							fdata.set(key, value);
 						}		
 					}
+				}
 				else {
 					Ut.each(reqOpts.vars, (val, key) => fdata.set(key, val));
 				}