How can I reinstall Bitdefender VPN on my Mac laptop?

I can't access Bitdefender VPN on my laptop anymore. I've had it on the laptop for years, but today, when the VPN window is open and I click on CONNECT, nothing happens. The VPN icon on the top of the bar on the laptop has gone dim and not longer responds.

How can I get the VPN to respond? I went to Bitdefender Central and it shows that the laptop is secure and has VPN, but it doesn't anymore.

Please help. Thank you