permission denied using grpc gateway through authentication (etcd version 3.0.10)

[amyXia1994]

I visit etcd server through grpc gateway with etcd auth enabled. I can get correct token but when use token to fetch key, it returns "etcdserver: permission denied". My etcd version is 3.0.10.

This problem does not occur when I test with etcd 3.3.8.

Does previous etcd version before 3.3 support fetching key with token via grpc gateway? Or can you please provide a way to config my 3.0.10 etcd to support that?
Solution besides updating etcd version is preferred since that takes extra efforts.

Here are my visit requests:
I can get correct token from username and password:

curl -s  http://host:port/v3alpha/auth/authenticate  -X POST -d '{ "name":"userName", "password":"pw" }'

but when I use the token to fetch key, I got "permission denied"

curl -L http://host:port/v3alpha/kv/range -H "Authorization : tokenIJustGot" -X POST -d '{"key": "bmFtZQ=="}'

That's the response:

{"Error":"etcdserver: permission denied","Code":9}

[gyuho]

/cc @joelegasse

[hexfusion]

@amyXia1994 auth was enabled with gRPC gateway as of v3.3 I am not sure if a plan exists to backport.

ref: #7999

[hexfusion]

@gyuho is backporting this feature something we are considering? If not this issue can be closed.