How I add search icon instead of text "Search" in search bar?

I want this

Instead of

I can input the icon in the button as a part of it. Also, I can’t delete this so that I can add a link block. How I can do this please help.

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

Use background image and svg icon. Add extra left padding (room for the icon).

To put the search button on top of the feild you can use position absolute (overlay).