JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" value="Valor fixo" 
    style="background: #EEE; cursor: not-allowed; color: #777"
    readonly />

<input type="text" value="Valor fixo 2" class="desabilitado" readonly />

CSS

.desabilitado {
    background: #EEE; 
    cursor: not-allowed; 
    color: #777;
}