Instlling KMymoney

Now that quicken has gone to a subscription format, and I'm an old retired person, I thought I would look for an alternative. KMymoney was recommended, but I can't get it installed due to the inability of the mac to know whether or not it is malware.

Normally there is an option to allow the install anyway, bypassing this problem. But I do not see the option there. Any fixes? Or is this software indeed malware?

Thanks