We have a section in our forum for writing. People can submit writing and people may make corrections or comments.
But not always. Correcting writing takes time and is not a particularly popular activity among the teachers who are on the forum- many of them have plenty of that to do at work and don't want to do more when they are relaxing on language forums.
I never correct writing. I used to, but it took up too much time and I spend much of my free time on the site anyway, so I decided a few years ago not to correct any more writing. There are many other teachers who do the same, some who correct occasionally and a few who will often correct writing.
However, if you're after proofreading, then going for a paid service that will give you dedicated time may be a better idea. Posting a ten-thousand word essay and saying it's urgent and expecting volunteers who are in the forum to discuss language to correct it in a hour is not very realistic.
If you post writing, it may get answers, but this is not guaranteed. There is no urgent turn-around time. We are volunteers and mostly prefer discussing language to correctng texts.