There are 2 button , one with the disabled property, and the second one not. It is necessary that when you click on the second button, the disabled property of the first one disappears.

 <button disabled id="btn1"></button> <button id="btn2"></button> 

    1 answer 1

    Just set the disabled property to false :

     document.querySelector('#btn2').addEventListener('click', e => document.querySelector('#btn1').disabled = false); 
     <button disabled id="btn1">Btn</button> <button id="btn2">OK</button> 

    • Your code for some reason does not work. - A.Hall
    • @ A.Hall, you probably have just an old browser. - user207618
    • Yes, I'm sorry, my mistake. - A.Hall