I wanna add new element (input when im create a new task) to the component of "gantt" HELP!

I’m trying to add a new element eg add a new select or input, but the only way I could find is to modify the gantt core in gantt.js, is there a way to do it from webix.ui?
i try to do something like
webix.ui({
view: “gantt”,
cols:[
{ view:“button”, value:“Load” },
{ view:“button”, value:“Save” },
{ view:“button”, value:“Info” }
],
});
But it does not work!
or some of the functions that webix has? if anyone could help me i needed to add a few more things and i would like to do it the right way as i couldn’t find anything that could help me in the doc.

to be more exact I would like to add more elements when I want to create a new task example I would like to add another input