Invalid Input: Group transaction does not need to be signed by Wallet user

Hello, I need some help regarding solving this error.
I have two transactions, one is signed by logicSign and other is supposed to be signed using WalletConnect.

const txnsToSign = txsToSign.map(txn => {
          const encodedTxn = Buffer.from(algosdk.encodeUnsignedTransaction(txn)).toString('base64');
          return {
            txn: encodedTxn,
          };
        });
        const txnsNotToSign = txsNotToSign.map(txn => {
          const encodedTxn = Buffer.from(algosdk.encodeUnsignedTransaction(txn)).toString('base64');
          return {
            txn: encodedTxn,
            signers:[]
          };
        });

These transaction are sent to

      const result = await this.walletConnect.sendCustomRequest(request);

And I receive this error.

Invalid Input: Group transaction does not need to be signed by Wallet user.

Can someone explain what this error means and what am I doing wrong?

Can you provide the full code generating request?
Can you show the content of request?

let requestObj= [];
 
txnsToSign.forEach(txn => requestObj.push(txn));
txnsNotToSign.forEach(txn => requestObj.push(txn));
        
 requestParams = [requestObj];
 const request = formatJsonRpcRequest('algo_signTxn', requestParams);
 const result = await this.walletConnect.sendCustomRequest(request);

Content of request are

{
    "id": 1639066971443128,
    "jsonrpc": "2.0",
    "method": "algo_signTxn",
    "params": [
        [
            {
                "txn": "iqNhbXTOABcCoKNmZWXNB9CiZnbOARjL3qNnZW6sdGVzdG5ldC12MS4womdoxCBIY7UYpLPITsgQ8i1PEIHLD3HwWaesIN7GL39w5Qk6IqNncnCAomx2zgEYz8ajcmN2xCDJzFnkCzYG1jryZ60AqJL4sobRx1lpSTmZkbq/3U1zEqNzbmTEIC6sZuam53L5EqDOE5vzm1Ptbzy+G93dZhyABDX6wiGSpHR5cGWjcGF5"
            },
            {
                "txn": "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",
                "signers": []
            }
        ]
    ]
}

I converted to JSON your two transactions using the Algorand software msgpacktool:

$ base64 -d <<< iqNhbXTOABcCoKNmZWXNB9CiZnbOARjL3qNnZW6sdGVzdG5ldC12MS4womdoxCBIY7UYpLPITsgQ8i1PEIHLD3HwWaesIN7GL39w5Qk6IqNncnCAomx2zgEYz8ajcmN2xCDJzFnkCzYG1jryZ60AqJL4sobRx1lpSTmZkbq/3U1zEqNzbmTEIC6sZuam53L5EqDOE5vzm1Ptbzy+G93dZhyABDX6wiGSpHR5cGWjcGF5 | msgpacktool -d -b32
{
  "amt": 1508000,
  "fee": 2000,
  "fv": 18402270,
  "gen": "testnet-v1.0",
  "gh:b32": "JBR3KGFEWPEE5SAQ6IWU6EEBZMHXD4CZU6WCBXWGF57XBZIJHIRA====",
  "grp": {},
  "lv": 18403270,
  "rcv:b32": "ZHGFTZALGYDNMOXSM6WQBKES7CZINUOHLFUUSOMZSG5L7XKNOMJA====",
  "snd:b32": "F2WGNZVG45ZPSEVAZYJZX443KPWW6PF6DPO52ZQ4QACDL6WCEGJA====",
  "type": "pay"
}

$ base64 -d <<< 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 | msgpacktool -d -b32
{
  "apaa": [
    "AAAAAACflz0=",
    "AAAAAAMDStc="
  ],
  "apap:b32": "AIQAMAABAQCQEAZGBMAVKAKOAFHQCQYBIUAUCAKCAFJQEQSOAJJU4ASCIUYRQIQSIEACIKBWDIABOZZJGYNACF3HFIZAGZZLGYOACZZHAQZAGZZHAURGOJYGEJTSGQZRBEZAGERREAZAGEQQIAAACABRDERREQAC3YYRSJBFCEJEAAIZGEMSCBASIABL6NQ2AATQMESAAIJTMGQAE4DREQABR43BUABHBAJEAAHYGYNAAJYJCJAABAJWDIACWESAABQTMGQAE4FBEQAAAEACOBLEEIJSUZBSAMJRAQAAAEACEJYGMIRBGQIAAYTQMJYFMRTTGAIHE4CGIERTAIACOBDECIIDGAYUFJSBEEBTAMACOBDECIIDGAYSE4CWIEQQIAAACABHAURGOKRSANTSEJYGEJTCGQZRAAVWIERHARSDEAYSCBAAAAIAE4CDMHABM4RUGIZHAZRCEEZTAIJCGJYGMIJBAMYCAATQIZASCAZQCBZHARSBEECAAAAQAIZHAYRGMJYGE4DGIIYJM4ZQGFBWDQAREQAAAEACUZBSAMJECAAMGMBQAMIACJAAAAIAENBSUZBRAAJECAAVGMBQAJYEMQJEAAABAATQKITHFIZAGZZDIMREGJYFMQRBGKTEGIBRGECAAAAQAIRHAZRCEE2BAAECOBRHAZSCGCLHGMBBIJYEMQJECAAMEITQMIRHAZRDGAQSBBTDGAQAE4CGIESBAAGCEJYGEITQMYRTAIJASZRCE4DGEJYFMQJDGAIHE4CGIEQQGMBQAJYEMQJBAMYECQVGIEQQGMCAAJYEMQJBAMYECITQKZASCBAAAAIAE4CSEZZKGIBWOIRHAYRGMI2DGICCCBASIEADMKTEGIBREJYFMQRBEEBTAEKCOBDECIIDGAIQEQJBAMYBCEUWIEQQGMAREIYSCAZQCABTAAABEECAAAAQAKRRABTTMGQBC4TQKZATFJSDCAASCBAAAAIAE4CTMGQBC5TTEBBBAUJECAARGMBAAJYEMQJEAAABAAVDEA3HENBSOBLEEIJUAAABAARUGIRHAZRDKAJSAQQQIESBAAXTGAIUE4CGIERTAEADGAAACIIDGAIQEQJBAMYBCEUGIEQQIAAACABCE4DCEJYGMIZQCEQIMYRTKABSAQQQKESBAAUDGAQAE4CGIERTAEDSOBDECIIDGAQSEIJRAQAAAEACEJYGEITQMYRTAIJASZRDGUADIABDCJAAAAIAEITQMYRCCM2ACIQSCBAQACBHAYTQMZBDBBTSEJYGMIRBENABEIJRAQIABATQMJYGMQRQSZZDIMRCOBTCEIJEAAABAARUGISDEITQMITGENBQ====",
  "apat": [
    "Lqxm5qbncvkSoM4Tm/ObU+1vPL4b3d1mHIAENfrCIZI="
  ],
  "apgs": {
    "nbs": 3,
    "nui": 4
  },
  "apls": {
    "nui": 1
  },
  "apsu:b32": "AIQACABGAEAUEIRIEJTA====",
  "fv": 18402270,
  "gen": "testnet-v1.0",
  "gh:b32": "JBR3KGFEWPEE5SAQ6IWU6EEBZMHXD4CZU6WCBXWGF57XBZIJHIRA====",
  "lv": 18403270,
  "lx:b32": "HEZTOMTCGU3DOZLGMI3TIZRZGU4GGMDBG43DCMDFG5STMYRZMJQQ====",
  "snd:b32": "ZHGFTZALGYDNMOXSM6WQBKES7CZINUOHLFUUSOMZSG5L7XKNOMJA====",
  "type": "appl"
}

As you can see the first transaction has "grp": {}, which is not authorized, while the second transaction has not "grp".
This means you have an issue in the way you assigned the group ID.

Did you follow Atomic transfers - Algorand Developer Portal ?

Thank you so much,
I was assigning groupID in the wrong way