POST http://keycloak-fixed-variant:8080/realms/test-realm/protocol/openid-connect/token
grant_type=urn:ietf:params:oauth:grant-type:token-exchange
subject_token_type=urn:ietf:params:oauth:token-type:jwt
subject_issuer=ext-idp
requested_token_type=urn:ietf:params:oauth:token-type:access_token
client_id=te-client
subject_token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwczovL2V4dGVybmFsLWlkcC1pc3N1ZXIiLCJzdWIiOiJiYXNpYy11c2VyLWlkIiwiYXVkIjoiaHR0cHM6Ly9leHRlcm5hbC1pZHAtaXNzdWVyIiwidHlwIjoiQmVhcmVyIiwiZXhwIjoxNzgzMjY3NTIxLCJpYXQiOjE3ODMyNjcyMjEsImp0aSI6IjJlYTg1OTBhLTgzNDItNDMyYi1iNDVkLTM3MDFkODhjZmEzNiJ9.l8ZETwtpZOtlBDnENNgaqTxhSIu1GvMq-PSWN0HgjE0