def create_jwt_token(secret, client_id):
assert secret, "<STR_LIT>"<EOL>assert client_id, "<STR_LIT>"<EOL>headers = {<EOL>"<STR_LIT>": __type__,<EOL>"<STR_LIT>": __algorithm__<EOL>}<EOL>claims = {<EOL>'<STR_LIT>': client_id,<EOL>'<STR_LIT>': epoch_seconds()<EOL>}<EOL>return jwt.encode(payload=claims, key=secret, headers=headers).decode()<EOL>
Create JWT token for GOV.UK Notify

Tokens have standard header:
{
    "typ": "JWT",
    "alg": "HS256"
}

Claims consist of:
iss: identifier for the client
iat: issued at in epoch seconds (UTC)

:param secret: Application signing secret
:param client_id: Identifier for the client
:return: JWT token for this request