186526 Generate 204 Service

For Captive Portal Server

For Android 5.x-6.x
Run adb command

adb shell "settings put global captive_portal_server http204.18l.xyz"

For Android 7.x-10.x
Run adb command

adb shell "settings put global captive_portal_http_url http://http204.18l.xyz/generate_204"
adb shell "settings put global captive_portal_https_url https://204.186526.xyz/generate_204"

JS Demo

(async () => {
    const result = await fetch("https://204.186526.xyz/generate_204");
    if (result.status === 204) {
        return true;
    } else {
        return false;
    }
})().then(e => { console.log(e); });

Not Checked