The example demonstrates how to move list item into folder via SharePoint JSOM API

SP.ListItem.moveTo.js

    var listTitle = "Requests"; //list title
    var itemId = 1;  //list item id
    var targetFolderUrl = "/Lists/Requests/Archive";  //target folder server relative url
    
    var ctx = SP.ClientContext.get_current();
    var list = ctx.get_web().get_lists().getByTitle(listTitle);
    var item = list.getItemById(itemId);
    ctx.load(item,['FileRef','FileDirRef']);
    ctx.executeQueryAsync(
       function(){
           var fileUrl = item.get_item('FileRef');
           var file = ctx.get_web().getFileByServerRelativeUrl(fileUrl);
           var targetfileUrl = fileUrl.replace(item.get_item('FileDirRef'),targetFolderUrl); 
           file.moveTo(targetfileUrl, SP.MoveOperations.overwrite);
           ctx.executeQueryAsync(
              function(){
                 console.log('List item has been moved');   
              },
              logError
           )
       },
       logError);
    
    
    function logError(sender,args){
          console.log(args.get_message()); 
    }