How to post firewall floating rules using the API?

[gsm84]

Hello,

I'm using the firewall plugins API to create rules - lan, wan, etc. but not able to create floating rules. The floating rule is only created when I select multiple interfaces but not when a single or no interface is selected. In case no interface is selected, the rule is added to LAN by default whereas I want it to be added to floating rules as in the opnsense frontend.

Any help is greatly appreciated.