I am { "error": "consent_required" } while generating the docusign JWT access token

private_key = OpenSSL::PKey::RSA.new(@config[:rsa_private_key])
jwt_payload = { iss: @config[:integration_key],
sub: @config[:user_id], iat: Time.now.to_i,
exp: Time.now.to_i + 3600,
aud: 'account-d.docusign.com',
scope: 'signature' 
}
response = HTTParty.post('https://account-id.docusign./oauth/token', body: { grant_type: 'urn:ietf:params:oauth:grant-type:jwt-bearer', assertion: JWT.encode(jwt_payload, private_key, 'RS256') })

I am using the above code with valid credentials to generate the docusign jwt token.
but it giving "consent_required" error.
previously same was working fine. but not working now.

Your Payload is not correct.
and do check your gem file you might have mistakenly removed the JWT gem.

try this:

private_key=OpenSSL::PKey::RSA.new(File.read('path/to/private_key.pem'))
jwt_payload = {
    iss: @config[:integration_key],
    sub: @config[:user_id],
    iat: Time.now.to_i,
    exp: Time.now.to_i + 3600,
    aud: 'account-d.docusign.com',
    scope: 'signature'
}
jwt_token = JWT.encode(jwt_payload, private_key, 'RS256')

Please note that this code assumes you have the necessary configurations (@config) in place and that you have the appropriate private key file for signing the token.

After generating the token, then you can pass it to the API request directly.

• scopes should be "signature impersonation" for JWT
• The correct URL is account-d.docusign.com for authentication
• Even if you do the above right, consent is still required, once pers user/IK combination. Read how to do it in this article - https://developers.docusign.com/platform/auth/consent/obtaining-individual-consent/

For Ruby code for JWT, I highly suggest you try quickstart and pick "Ruby" and "JWT" which will ensure you get a working configured code that just works.