keyboard tab with Easy Font Resize

Dear Sir/Madam,

We are using Easy Font Resize plugin. Due to website accessibility, we would like to enable the viewers to use keyboard tab to click the A A A buttons. However, the Easy Font Resize doesn’t response to the keyboard tab, when I pressed “tab”, our website skipped all the three AAA buttons and goes straight to the other buttons.

We have the following CSS code:

:root {
–focus-black: #383838;
}

:focus-visible {
outline: 2px solid var(–focus-black) !important;
}

a:focus-visible {
outline: 2px solid var(–focus-black) !important;
}

button:focus-visible {
outline: 2px solid var(–focus-black) !important;
}

Please kindly advise how we could use keyboard tab with Easy Font Resize.

Thanks & regards,
KF