[en] WCAG 2 FAQ

Some site says for link text color contrast should be 4.5:1 and some site
says link text should be 3.1:1. Can you pls clarify at what situation that
3:1 color contrast is sufficient for link text.

Sometimes link text designed like a button so what should be the minimum
color contrast required for the button like link text.

Best regards,
Ragavendra