I'm passing this URL into the verifier; /go-api/v1.0/meta/callbacks/admob/2?ad_network=4970775877303683148&ad_unit=1000666186&reward_amount=1&reward_item=Key%20Doubler×tamp=1584354656623&transaction_id=19808b2d2660df761d5a3259a3d6fbc6&user_id=GbgZbUuAyUgbyTZYQUA2eGNLsjh1&signature=MEUCIBAEW1jAC72wybEVSeexWF4LESQ7Nkoypy3y1swVDAUvAiEAhKsB68Myzr0N3_dEHFTeeRRlFYFkmyPGW6I5hSEkIGw&key_id=3335741209
But we always get a "Signature not valid" error. Can't seem to understand why though.