Swahl. There is a way to do de-essing with a DA-7 and no other processing. But for all the gymnastics it takes setting it up... it's better just to insert a hardware de-esser in a channel send/return.

Plugins... only familiar with what there is here and there's one supplied with Pro Tools software. One that came with Waves Diamond bundle. The Waves stuff is a little more flexible than the stock PT plugin. Either can just be used as an insert on the channel {s} that need de-essing.

But you can also do frequency dependent compression {which is what a de-esser is anyway} via a compressor's side chain input. This goes for hardware or plugin compressors.... hardware as long as the compressor has a side chain input. Either/or requires multing the vocal. One as the straight {or passed/heard} signal. One not heard, to feed the side chain of the compressor that's inserted on the straight vocal channel. The idea is, to hit the compressor's side chain with the frequency band you want to compress. There's some hit/miss here but if the secondary/multed vocal triggering the side chain, is eq'd with a big, narrow Q boost between 4k and 12k, that compresses the primary vocal track... But only when those frequencies are present. Like on S's, T's etc. It'll always be a little different from singer to singer, and gender as far as what works. Same thing for plosives... but there the secondary vocal will need a much lower frequency to trigger the side chain.
I'm probably hypersensitive and too familiar from editing the heck out of Justin's tune. But there's a popping P on the third line {word "hope"} that's really bad. It can go by un-noticed because it almost sounds like a kick drum hit. This one can just be snipped out of the vocal track without any of the above.