You need to be a customer of Tmobile USA and meet the requirements in the link below. If you aren't a Tmobile USA customer there is nothing they can do to help.

https://www.t-mobile.com/responsibility/consumer-info/policies/sim-unlock-policy

Dear T mobile customer service 

Please unlock carrier of this device having imei no. 351048913558221 or IMEI2= 351048918437140

I purchased this phone from UAE Secondhand. My native land is Bangladesh. I am currently in Bangladesh,,,please unlock my phone,,,my iCloud id My mother is very sick,,couldn't contact anyone,,I don't have money to buy another phone,,,please

I purchased this phone from UAE Secondhand. My native land is Bangladesh. I am currently in Bangladesh,,,please unlock my phone,,,my iCloud id: My mother is very sick,,couldn't contact anyone,,I don't have money to buy another phone,,,please

Did you read the best answer? Tmobile can't unlock it because you not a customer.