// Target: <div class="indiCaptchaQ"><img src="..."></div>
var cap_target = document.querySelector(".indiCaptchaQ img").src;

// Grid list: <button class="cap-btn"><img src="..."></button>
var captcha_grid = document.querySelectorAll(".cap-btn img");

for (let i = 0; i < captcha_grid.length; i++) {
    let cap = captcha_grid[i];
    if (cap.src === cap_target) {
        // Option A: Click the image itself
        cap.click();
        
        // Option B: If clicking the image doesn't trigger the button, 
        // uncomment the line below to click the parent <button> instead:
        // cap.closest('.cap-btn').click();
    }
}

// Next btn
// document.getElementById("step-go").click();