Proxy reset for Optionlist

I have a list of options like

   id: 'city_id',
   suggest: common.table.sizing(),
   header: [, {content: 'selectFilter', compare: common.table.stringCompare}],
   minWidth: 120,
   options: 'getOptions->Cities',
   sort: 'text'

the customer proxy getOptions (cities in this case) is:

 webix.proxy.getOptions = {
    load: function(view,params){
      let source = this.source;
      let result =;
          console.log('load '+source+' options from cache');
          return result;
      let url = '/'+source+'/getOptions';
      return webix.ajax(url,function(text,data){
          console.log('load '+source+' options from server');
 , data.json());

It will not load from server but from cache somewhere and I can not update while databases content has been changed! How can I reset this proxy so it will be forced to load from server again!??

like a proxy reset or something. Is it possible that I didn’t understand the concept for the proxy mechanism at all?

Please for help and have a nice xmas