Style seems not work with web interface ?

[acinmavi]

I want to add some pause to the audio using web interface . Add comma (,) or dot (.) worked , but I want to pause with longer time (example 1 second).
I tried some way to use style prompt <sos/eos>sp1sp0 <sos/eos> but the audio seem not consider prompt as "pause"
Could you please give me a suggestion to use these prompt ? Or please suggest how to make a pause with custom long time ?