Error validating a transaction with blockcypher

I’ve created a testnet transaction using blockcypher API (https://api.blockcypher.com/v1/btc/test3/txs/new) and then signed the transaction using the signer (go lang). And then sent signed transaction to blockcypher (https://api.blockcypher.com/v1/btc/test3/txs/send)

But it’s returning error:

Error validating generated transaction: Error running script for input 0 referencing e41a5ceca53f2cd6076f3a100137d6182d0bd567d91e508f4171712b9c67f429 at 0: Script was NOT verified successfully.

The response I’m receiving:

{
  "errors": (
    {
      "error": "Error validating generated transaction: Error running script for input 0 referencing e41a5ceca53f2cd6076f3a100137d6182d0bd567d91e508f4171712b9c67f429 at 0: Script was NOT verified successfully."
    }
  ),
  "tx": {
    "block_height": -1,
    "block_index": -1,
    "hash": "c514900d8ed184c37bd795c30f24d56508c40ca5f65c2bf8d724162fd8976353",
    "addresses": (
      "tb1qy0jm6vmy2vmndpzzj34z6h6xnelta98d0ukf6s",
      "tb1qwchaysp9wfukq54yee8uye20f2c5zkpl97elvx"
    ),
    "total": 3996400,
    "fees": 3600,
    "size": 222,
    "vsize": 141,
    "preference": "low",
    "relayed_by": "2a01:4f8:192:6027::2",
    "received": "2021-05-01T09:34:02.926591638Z",
    "ver": 1,
    "double_spend": false,
    "vin_sz": 1,
    "vout_sz": 2,
    "confirmations": 0,
    "inputs": (
      {
        "prev_hash": "e41a5ceca53f2cd6076f3a100137d6182d0bd567d91e508f4171712b9c67f429",
        "output_index": 0,
        "output_value": 4000000,
        "sequence": 4294967295,
        "addresses": (
          "tb1qwchaysp9wfukq54yee8uye20f2c5zkpl97elvx"
        ),
        "script_type": "pay-to-witness-pubkey-hash",
        "age": 1973087,
        "witness": (
          "3045022100a4a53cc0eaae807e5c3500af2132a8e575823fc0ff7ceb92de94b739920810ba0220339aa4128967654977b6afb8be9a8897c5e822e2cb5659fe987c106bec44101e",
          "03f2cfd459014d4f19f36e28dcae329ca4f6b263d4d7c13ca7317a75b1a130f0f6"
        )
      }
    ),
    "outputs": (
      {
        "value": 2000000,
        "script": "001423e5bd33645337368442946a2d5f469e7ebe94ed",
        "addresses": (
          "tb1qy0jm6vmy2vmndpzzj34z6h6xnelta98d0ukf6s"
        ),
        "script_type": "pay-to-witness-pubkey-hash"
      },
      {
        "value": 1996400,
        "script": "0014762fd2402572796052a4ce4fc2654f4ab141583f",
        "addresses": (
          "tb1qwchaysp9wfukq54yee8uye20f2c5zkpl97elvx"
        ),
        "script_type": "pay-to-witness-pubkey-hash"
      }
    )
  },
  "tosign": (
    ""
  )
}

Any help would be greatly appreciated. Thank you all.