spreadtrum 7731g frp not working

triyng to bypass frp for a majestic tablet but not works.
is this function only for huawei spd phones?


SigmaKey v.2.28.03
xxxxxxxxx Sigma dongle 2.28, Initializing...OK
Pack 1: Activated
Pack 2: Activated
Pack 3: Activated
--------- 2018-07-23 13:37:55 ---------
SigmaKey 2.28.03 Sprd: Remove FRP / Huawei ID
Getting info...Unexpected response from the phone
--------- 2018-07-23 13:46:31 ---------
SigmaKey 2.28.03 Sprd: Remove FRP / Huawei ID
Getting info...Unexpected response from the phone

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