I am using from react-select but I am not able to remove spinners/arrows from the dropdown.

I am able to remove the default separator | and Dropdown Indicator using
<Select
  components={{
    IndicatorSeparator: () => null, DropdownIndicator: () => null
  }}
  {...}
/>
But how can I get rid of these arrows?
                        
I believe you're setting the
type=numberfor theinputelement somewhere. In order to remove the up/down arrow. you can use the css code from this tutorial.You can also see all of the input types and how it's rendered out-of-the-box here.
Live Demo