How to list an item on steam market

[Guest Sampli]

function sellItem(item, price, sessionID, callback) {
    var options = {
          url: 'https://steamcommunity.com/market/sellitem/',
          headers: {
              'Accept': '*/*',
              'Origin': 'http://steamcommunity.com',
              'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.116 Safari/537.36 OPR/67.0.3575.130',
              'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
              'Host': 'steamcommunity.com',
              'Origin': 'https://steamcommunity.com',
              'Referer': 'http://steamcommunity.com/profiles/'+client.steamID.getSteamID64()+'/inventory/',
              'Accept-Encoding': 'gzip, deflate, br',
              'Accept-Language': 'en-US,en;q=0.9',
              'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'
          },
          form: {
              sessionid: sessionID,
              appid: item.appid,
              contextid: item.contextid,
              assetid: item.assetid,
              amount: 1,
              price: 1
          }
      };

      request(options, function (error, response, body) {
          if(!error && response.statusCode == 200){
              console.log("Item added on market");
          }else{
              console.log(error);
              console.log(body);
              console.log(response);
              console.log(response.statusCode);
          }
      });
}

This is my post request, which throws a http error 400 (bad request) every time. I don't know what i'm doing wrong.

[vrtgn]

Are you passing/setting cookies?

[Guest Sampli]

28 minutes ago, vrtgn said:

Are you passing/setting cookies?

No, but I'm getting cookies generated by steam in my response.

[vrtgn]

Try changing the referer to https.

[Guest Sampli]

13 minutes ago, vrtgn said:

Try changing the referer to https.

Didn't do anything, sorry.

I ended up figuring it out using the request method.

[vrtgn]

Was it because you weren't posting?

[Guest Sampli]

Just now, vrtgn said:

Was it because you weren't posting?

I have no idea... but it works so i'm not complaining