How to get BTCPAY_KEY to pair BTCPay NodeJS client?

[savshit]

Hello,
I have execute below command to generate private key :
node -p "require('btcpay').crypto.generate_keypair()"

output :

KeyPair {
  ec: EC {
    curve: ShortCurve {
      type: 'short',
      p: [BN],
      red: [Red],
      zero: [BN],
      one: [BN],
      two: [BN],
      n: [BN],
      g: [Point],
      _wnafT1: [Array],
      _wnafT2: [Array],
      _wnafT3: [Array],
      _wnafT4: [Array],
      _bitLength: 256,
      _maxwellTrick: true,
      redN: [BN],
      a: [BN],
      b: [BN],
      tinv: [BN],
      zeroA: true,
      threeA: false,
      endo: [Object],
      _endoWnafT1: [Array],
      _endoWnafT2: [Array]
    },
    n: BN { negative: 0, words: [Array], length: 10, red: null },
    nh: BN { negative: 0, words: [Array], length: 10, red: null },
    g: Point {
      curve: [ShortCurve],
      type: 'affine',
      precomputed: [Object],
      x: [BN],
      y: [BN],
      inf: false
    },
    hash: [Function: SHA256] {
      blockSize: 512,
      outSize: 256,
      hmacStrength: 192,
      padLength: 64
    }
  },
  priv: BN {
    negative: 0,
    words: [
      60122369,  6539265,
      32022909, 18000869,
      54800933, 37009431,
      11861628, 15322106,
      12775509,  2015340,
             0
    ],
    length: 10,
    red: null
  },
  pub: null
}

then i move further to pair client to server:

# Replace the BTCPAY_XXX envirnoment variables with your values and run:

$ [space] BTCPAY_URL=https://mydomain.com/ BTCPAY_KEY=... BTCPAY_PAIRCODE=... node -e "const btcpay=require('btcpay'); new btcpay.BTCPayClient(process.env.BTCPAY_URL, btcpay.crypto.load_keypair(Buffer.from(process.env.BTCPAY_KEY, 'hex'))).pair_client(process.env.BTCPAY_PAIRCODE).then(console.log).catch(console.error)"

# (prepend the line with a space to prevent BTCPAY_KEY from being saved to your bash history)

>>> { merchant: 'XXXXXX' }

Here i have set BTCPAY_URL = https://testnet.demo.btcpayserver.org/
BTCPAY_KEY = not found, where to get it?
BTCPAY_PAIRCODE= 'fLkLhsX'

Where I get BTCPAY_KEY and use it in the above code?
can anyone guide me on how to pair the client to the server with the BTCPAY server node library?

[savshit]

generate private key : node -p "require('btcpay').crypto.generate_keypair().getPrivate('hex')"
generate public key : node -p "require('btcpay').crypto.generate_keypair().getPublic(true|false, 'hex')"

use the above command to generate private and public key and use it to pair client to server.

[NicolasDorier]

@savshit this create two different keypair.

[takinbo]

@savshit you only need the value for BTCPAY_KEY, so you only need the first command.