Lets assume you are using Google Chrome on that Android. If you are not, it might not be the same. But if you have Chrome, lets try that.
- On the browser top bar you will see three vertical dots.
- Tap those, a menu will open.
- On the top of the menu there will be an i in a circle (i for information). Tap that
- You should see a notice about mic allowed or blocked. And on the lower right "site settings". Tap site settings
- On the screen that opens up, there is a "permissions" section. You can tap on the mic permission here to deny or allow it.