I can't install mullvadvpn on Fedora 40

Every time I try to run:

sudo dnf config-manager --add-repo https://repository.mullvad.net/rpm/stable/mullvad.repo

I get the following message:

Adding repo from: https://repository.mullvad.net/rpm/stable/mullvad.repo

Curl error (60): SSL peer certificate or SSH remote key was not OK for https://repository.mullvad.net/rpm/stable/mullvad.repo [SSL certificate problem: unable to get local issuer certificate]

Error: Configuration of repo failed

Does anyone know how to resolve this?