Clicking a phone number in macOS Catalina starts Skype instead of making the call from my iPhone

Using macOS Catalina 10.15.6 and Skype 8.64.0.80.

Clicking a phone number (or selecting "Call [phone number] Using iPhone") does not make a call from my iPhone, but instead automatically starts Skype and takes me to its dial pad with the phone number pasted there, offering a free trial of Skype to Phone.

I cannot find any way to disable this behaviour, neither in Skype's preferences nor in the macOS system preferences. I don't want to use Skype to make calls, and I never did. This is just another example of Microsoft's aggressive tactics to try to force people to use their terrible software.

Has anyone else encountered this issue, or have any knowledge of how to fix it? Thanks in advance.