g955u Imei: 000000000000000

g955u t-mobile came for unlock, when i read info the imei is all 0 and FINAL IMEI certi fail, how to get back imei for unlock
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Model: SM-G955U
Sales Code: TMB
Country Code: USA
Timezone: Asia/Colombo
Android Version: 8.0.0 [R16NW] [SDK 26]
Build Date: Mon Feb 26 17:50:21 KST 2018
PDA Version: G955USQU2CRB9 [february 2018, rev9]
Phone Version: G955USQU2CRB9 [february 2018, rev9]
CSC Version: G955UOYN2CRB9 [february 2018, rev9]
Product Code: TMB
HIDSw Version: G955USQU2CRB9/G955UOYN2CRB9/G955USQU2CRB9/G955USQU2CRB9
Board Platform: MSM8998
Modem Platform: MSM8998
Serial Number: R28J72L1ZWE
Imei: 000000000000000
Unique Number: 9889DB333232513852
Connections: AT,MTP
Battery Status: 3.76V (36%)
Network Type: GSM
SIM Status: READY
Multisim Config: SS
Knox Version: v30
Warranty Bit: 0
Security Patch: 2018-02-01
Data Encryption State: encrypted