How to use the "The Render URL API" with Series (i.e:sumSeries(#A, #B))

Hello when I have have a simple metric I can use the render api, for example:
http://IP:PORT/render/?target=alias(,'my kpi1)&format=csv http://IP:PORT/render/?target=alias(ott.5min.spp.*.host*.0.requests,'my kpi1)&format=csv

But If I have a more complex metric like:
C:alias(sumSeries(#A, #B),‘Total’)
how can I do it in that case?

Thanks in advance