Manual entering SimBrief flightplan with two different Cruise Flight Levels

I am flying mostly FBW 32nx and PMDG 737-800. I’m using simbrief with my route planning. I recently had a couple of routes that had two different Flight Levels steps at cruise, first FL210 and than FL180. How do I enter this when I am entering this manually in the MCDU or CDU? I can only enter one value into the FL section of INIT…

Moved to #third-party-addon-discussion:aircraft as these are non-stock jets. Use #self-service:aircraft-systems for stock sim airplanes only. Thanks.

you can change the constraints on the legs/F-PLN Page entered as speed/altitude. To change just speed enter speed/ and to change just altitude do /altitude

Example:
WP1 .78/FL210
WP2 .78/FL180

in INIT set the cruise to your final cruise level. That said you can also tell SB not to include step climbs. Typically it goes from a lower altitude for a higher one for step climbs but you do you

Not only that, you generally don’t need to step climb in those planes…generally