Unable to exchange token from google identity provider access token to Keycloak token

I enabled the permissions in both client and idp and update the both permissions also add client policy in both permissions then still i am unable to exchange token

Api Curl
curl --location ‘http://localhost:8888/realms/4c9dce31-42be-43ee-aa22-7f8f6d5856f6/protocol/openid-connect/token
–header ‘Content-Type: application/x-www-form-urlencoded’
–data-urlencode ‘client_id=walm_dee1d8a30a324376’
–data-urlencode ‘client_secret=82b48e5e123643b0b2ab2e0caed8f6cd’
–data-urlencode ‘subject_token=${access_token}’
–data-urlencode ‘requested_issuer=google’
–data-urlencode ‘grant_type=urn:ietf:params:oauth:grant-type:token-exchange’
–data-urlencode ‘requested_token_type=urn:ietf:params:oauth:token-type:access_token’

2024-07-10 12:28:33,275 WARN [org.keycloak.events] (executor-thread-349) type=“TOKEN_EXCHANGE_ERROR”, realmId=“d635c9c8-6b34-4e11-afe0-54d70c012135”, clientId=“walm_dee1d8a30a324376”, userId=“null”, ipAddress=“0:0:0:0:0:0:0:1”, error=“invalid_token”, reason=“subject_token validation failure”, auth_method=“token_exchange”, grant_type=“urn:ietf:params:oauth:grant-type:token-exchange”, client_auth_method=“client-secret”

{
“error”: “invalid_token”,
“error_description”: “Invalid token”
}

when i chage the requested_issuer to subject_issuer and requested_token_type to subject_token_type
then this comes
2024-07-10 12:36:46,142 WARN [org.keycloak.events] (executor-thread-349) type=“TOKEN_EXCHANGE_ERROR”, realmId=“d635c9c8-6b34-4e11-afe0-54d70c012135”, clientId=“walm_dee1d8a30a324376”, userId=“null”, ipAddress=“0:0:0:0:0:0:0:1”, error=“federated_identity_account_exists”, auth_method=“token_exchange”, grant_type=“urn:ietf:params:oauth:grant-type:token-exchange”, subject_issuer=“google”, validation_method=“user info”, client_auth_method=“client-secret”

{
“error”: “invalid_token”,
“error_description”: “User already exists”
}