No idea ... sorry.
Maybe a TAB account is more fun and will cost A LOT less ?
BY your question and being a newbie ... or learning which is a good thing ... No offense meant, I am still learning many moons and decades latter.
Shorting shares ... is actually MARGIN whatever you may think. Your granting unlimited upside ... so you think a share goes down. It invents cold fusion and the 10 cent share goes on hold whilst announcement made comes back at $1,000- or $1- million. Less dramatic say a miming company discovers a massive deposit and your bet ... hoping you loose only say 10% on 50k, turns out to be 2000% or a total loss of 100k v an expected 5 k loss.
Not a fan of shorts, even with many years experience , not in the case of specific risk ... that being over a single share .... often your betting against stupidity and whilst a company may come out with shocking news, and your right, in the meantime it can rally 100% and your wiped out when say 2 years latter its worth 2 cents verses the 50 cents starting point.
Non specific risk or market risk even at times is not for the less experienced people. At times one blinks and its up or down a few percent .... even 5% or say 9/11 ... 15% ..
good luck